The PPC bidding strategy in a campaign is the mechanism that determines how Google deploys the budget to compete in the real-time auction. It is one of the most commercially significant decisions in campaign management — the wrong bidding strategy for the campaign’s objective and data maturity wastes budget, limits volume, or pursues the wrong outcome entirely.
The range of available bidding strategies in Google Ads spans from fully manual (the advertiser sets every bid individually) to fully automated (Google’s machine learning algorithm sets every bid in real time based on a defined objective). The trend in the industry has been strongly toward automated strategies — Google’s smart bidding algorithms consistently outperform manual bidding for accounts with sufficient conversion data. But the key phrase is “with sufficient conversion data” — automated strategies fail predictably when deployed on campaigns without the conversion history that trains the algorithm.
This guide covers every major Google Ads bidding strategy, what each optimises for, when each is appropriate, and the common deployment mistakes that undermine performance.
Manual CPC: Full Control, High Maintenance
Manual CPC allows the advertiser to set a specific maximum cost-per-click bid for each keyword. Google will not bid more than the specified maximum for any click on that keyword.
What it optimises for: the advertiser’s judgment about the value of each click, expressed as a maximum CPC.
When to use it:
Manual CPC is most appropriate in three situations. First, when launching a brand new campaign with zero conversion history — there is no data for automated strategies to optimise against, so manual bidding allows controlled initial data collection. Second, for very small campaigns with low keyword counts where manual management is feasible. Third, for campaigns targeting very specific informational keywords where the primary objective is impressions or traffic rather than conversion.
The limitations:
Manual CPC requires constant monitoring and adjustment to maintain competitive position as the auction landscape changes. An advertiser setting bids monthly and leaving them unchanged is effectively bidding on historical data — the auction of six weeks ago may bear little resemblance to today’s competitive environment. The resource cost of maintaining effective manual bidding at scale is significant.
Enhanced CPC (ECPC): A hybrid of manual and automated. The advertiser sets manual CPC bids; Google automatically adjusts individual bids up or down based on the predicted likelihood of conversion. ECPC provides machine learning input while retaining manual bid ceilings. It is often a useful transitional strategy between manual and fully automated bidding.
Maximise Clicks: Volume Over Efficiency
Maximise Clicks automatically sets bids to generate the maximum number of clicks within the campaign’s daily budget — without any conversion objective.
What it optimises for: click volume within a budget constraint.
When to use it: Maximise Clicks is appropriate when the objective is traffic volume — driving visitors to a new website, building awareness in a new market, or testing keyword performance before conversion tracking is in place. It is explicitly not a conversion-optimised strategy and should not be used when the objective is leads, sales, or revenue.
The risk: Maximise Clicks will find the cheapest clicks available — which are not necessarily the most qualified clicks. It can drive high traffic volumes at low average CPC while delivering visitors with low purchase intent. Monitor the quality of traffic alongside the volume.
Target Impression Share: Owning Specific Positions
Target Impression Share sets bids to achieve a defined proportion of eligible impressions in a specified ad position — at the top of the page, absolute top of the page, or anywhere on the page.
What it optimises for: visibility and position share, not conversion.
When to use it: Brand campaigns where the objective is ensuring the brand appears for its own name in every relevant search. Defensive bidding against competitors bidding on brand terms. Awareness campaigns where impression share is the primary success metric.
The limitation: Position targeting is expensive — achieving 95% impression share at the absolute top of the page requires bidding aggressively regardless of conversion probability. This strategy makes sense for brand terms where the volume is controlled and the objective is defensive. It does not make sense for generic commercial keywords where conversion efficiency should drive bidding.
Maximise Conversions: Volume-Optimised Automated Bidding
Maximise Conversions automatically sets bids to achieve the maximum number of conversions within the campaign’s daily budget, without targeting a specific cost per conversion.
What it optimises for: conversion volume within budget, without a cost efficiency constraint.
When to use it: Maximise Conversions is the recommended starting point when launching a campaign that has conversion tracking in place but insufficient conversion history for Target CPA to function effectively (fewer than 30 to 50 conversions in the last 30 days). It generates conversion data while spending the full budget — building the conversion history that enables transition to Target CPA.
The risk: Without a cost per acquisition constraint, Maximise Conversions can produce high conversion volume at poor economics — generating many low-value conversions while ignoring the budget allocation that would produce the best cost per acquisition. Transition to Target CPA once sufficient conversion history is accumulated.
Target CPA: The Standard for Lead Generation
Target CPA (Target Cost Per Acquisition) tells Google’s algorithm the average cost per conversion the advertiser is willing to pay. Google’s machine learning adjusts bids in real time — bidding more aggressively in auctions with high predicted conversion probability and less aggressively in auctions with low predicted probability — to achieve the target CPA across the full campaign.
What it optimises for: conversion volume at a defined average cost per conversion.
When to use it: Target CPA is the standard bidding strategy for lead generation campaigns with a clear, tracked conversion action (form submission, phone call, quote request) and a defined acceptable cost per lead. It is appropriate once the campaign has accumulated at least 30 to 50 conversions in the past 30 days — the minimum data volume for the algorithm to function reliably.
Setting the Target CPA correctly: The target must be set at a level that is both commercially viable (producing a positive return from the generated leads) and achievable given the campaign’s historic performance. A Target CPA set significantly below the campaign’s historic average will cause the algorithm to underbid — reducing impression share and conversion volume in pursuit of an unachievable target. Start at or slightly above the historic average CPA and reduce gradually as the algorithm optimises.
The lead quality consideration: Target CPA optimises for the conversion action defined in the account — form submissions, for example. If some form submissions are high-quality leads and others are not, the algorithm cannot distinguish between them. Offline conversion tracking — importing closed deal values or lead quality scores back into Google Ads — enables the algorithm to optimise toward actual revenue rather than raw lead volume.
Target ROAS: The Standard for E-Commerce
Target ROAS (Target Return On Ad Spend) tells Google’s algorithm the target ratio of revenue to ad spend. An advertiser setting a Target ROAS of 400% is saying they want £4 of revenue for every £1 spent on ads.
What it optimises for: revenue return on ad spend, at the defined target ratio.
When to use it: Target ROAS is the standard bidding strategy for e-commerce campaigns where different products have different revenue values — the algorithm can weight its bidding toward auctions likely to produce higher-value purchases. It requires conversion value data (order values passed through conversion tracking) and a minimum of 50 conversions with conversion values in the last 30 days.
The distinction from Target CPA: Target CPA treats all conversions as equally valuable. Target ROAS weights bids toward higher-value conversions. For an e-commerce business with products ranging from £20 to £500, Target ROAS produces materially better economics than Target CPA because it prioritises spend on the most valuable purchase opportunities.
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Maximise Conversion Value: Budget-Constrained ROAS Optimisation
Maximise Conversion Value automatically sets bids to achieve the maximum total conversion value within the daily budget — without targeting a specific ROAS ratio.
What it optimises for: total revenue within budget, without a ROAS efficiency constraint.
When to use it: When launching conversion value tracking for the first time and building the data needed for Target ROAS. The relationship to Maximise Conversions is parallel — Maximise Conversion Value is the data-building precursor to Target ROAS, just as Maximise Conversions is the precursor to Target CPA.
For Google Ads official bidding strategy guidance, check: Google Ads — about bidding strategies
Choosing the Right Strategy: The Decision Framework
The correct bidding strategy depends on three variables: the campaign’s objective (traffic, leads, sales, visibility), the availability and quality of conversion tracking, and the maturity of the campaign’s conversion data.
For a new campaign with no conversion history: Manual CPC or Maximise Clicks to generate initial data.
For a campaign with conversion tracking but fewer than 30 conversions in 30 days: Maximise Conversions to build the data the algorithm needs.
For a lead generation campaign with 30+ monthly conversions: Target CPA.
For an e-commerce campaign with 50+ monthly conversions and conversion values: Target ROAS.
For a brand visibility or impression share objective: Target Impression Share.
The most common mistake is jumping to Target CPA or Target ROAS on a campaign with insufficient conversion data. The algorithm has nothing to learn from — it makes arbitrary decisions, performance is erratic, and the result is poor CPA or ROAS that leads the advertiser to incorrectly conclude automated bidding does not work.
Evershare manages PPC campaigns with the bidding strategy discipline that campaign objectives and data maturity require — starting correctly, transitioning at the right data thresholds, and continuously optimising toward commercial outcomes. Contact Evershare today.
For independent PPC benchmarks and strategy research, check: WordStream — PPC bidding strategy guide
Conclusion
PPC bidding strategies range from fully manual to fully automated, each optimising for a different objective and requiring different data maturity to perform effectively. The correct strategy depends on the campaign’s objective, whether conversion tracking is in place, and whether sufficient conversion data exists for automated algorithms to learn from. Automated strategies — particularly Target CPA and Target ROAS — consistently outperform manual bidding for accounts with sufficient data. The failure mode is deploying them before the data threshold is reached.
Frequently Asked Questions
What are the main PPC bidding strategies?
The main Google Ads bidding strategies are Manual CPC (advertiser-set bids per keyword), Maximise Clicks (automated volume maximisation), Target Impression Share (position targeting), Maximise Conversions (automated conversion volume maximisation), Target CPA (automated bidding toward a cost per conversion target), Target ROAS (automated bidding toward a revenue return target), and Maximise Conversion Value (automated revenue maximisation within budget).
When should I use Target CPA bidding?
Use Target CPA when the campaign has accumulated at least 30 to 50 conversions in the past 30 days and has a clearly defined, accurately tracked conversion action. Set the Target CPA at or slightly above the campaign’s historic average CPA initially, then reduce gradually as the algorithm optimises. Target CPA is the standard bidding strategy for lead generation campaigns with stable, adequate conversion volume.
What is the difference between Target CPA and Target ROAS?
Target CPA optimises toward a defined average cost per conversion — treating all conversions as equally valuable. Target ROAS optimises toward a defined return on ad spend — weighting bids toward higher-value conversions. Target CPA suits lead generation campaigns where conversions have roughly equal value. Target ROAS suits e-commerce campaigns where different products have different revenue values.
Why is smart bidding better than manual CPC?
Google’s smart bidding algorithms process hundreds of auction-time signals — device, location, time of day, query intent, audience segment, and more — that are impossible to account for manually. For accounts with sufficient conversion data, this signal processing consistently produces better cost per conversion and conversion volume than manual bid management. Smart bidding fails only when deployed without adequate conversion data, or when the conversion tracking is incomplete or inaccurate.