How Google Ads Bidding Strategies Work (And Which to Use)
Google Ads bidding strategies determine how Google spends your budget to achieve campaign objectives — whether that means maximising clicks within a budget, targeting a specific cost-per-conversion, or optimising for revenue. The choice of bidding strategy has a direct impact on campaign performance, and selecting an approach that does not match your data volume or business goals is one of the most common causes of wasted ad spend.
This guide explains how each major google ads bidding strategy functions, when to use each one, and how to transition between strategies as your account matures.
Manual vs Automated Bidding
At a high level, Google Ads offers two bidding approaches:
- Manual bidding: You set a maximum cost-per-click (CPC) for each keyword. Google will not exceed that bid in any auction. You retain full control but must manage bids manually based on performance data.
- Automated (Smart) bidding: Google’s algorithm adjusts bids in real time based on auction signals — device, location, time of day, user behaviour, and more — to optimise toward a target you define. Automated strategies require conversion data to function effectively.
Manual bidding gives maximum control but requires significant time investment and expertise to manage effectively across large keyword sets. Automated bidding can outperform manual strategies when conversion volume is sufficient for the algorithm to learn — but underperforms when data is sparse.
Core Automated Bidding Strategies
Maximise Clicks
Google automatically adjusts bids to get the most clicks possible within your daily budget. This strategy does not optimise for conversions or conversion value — only traffic volume. It is appropriate for new campaigns in the early testing phase where the primary goal is gathering data, or for campaigns where the conversion happens offline and cannot be tracked in the platform.
Target Impression Share
Google adjusts bids to achieve a defined percentage of impression share in a chosen position (anywhere on the page, top of page, or absolute top). This strategy is designed for brand protection and awareness campaigns rather than direct response. It is also used to dominate impression share on branded terms to prevent competitor conquest. It does not optimise for conversions.
Maximise Conversions
Google uses all available budget to generate the maximum number of conversions, without a defined CPA target. This strategy works well when you want to drive as many conversions as possible and are less constrained by a specific cost-per-acquisition. It requires conversion tracking to be set up correctly. Without conversion data, the algorithm has no signal to optimise toward.
Target CPA (Cost Per Acquisition)
Google adjusts bids to achieve an average CPA as close as possible to your defined target. This is one of the most commonly used automated strategies for lead generation campaigns. The algorithm will raise or lower bids on individual auctions based on the predicted probability of conversion, staying within the overall CPA target across the campaign.
Target CPA requires a minimum of 30–50 conversions per month for the algorithm to optimise effectively. Below this threshold, the algorithm lacks sufficient data to make reliable predictions and performance is often erratic. If your campaign does not yet have this volume, run Maximise Conversions first to build the data foundation before switching.
Target ROAS (Return on Ad Spend)
Google adjusts bids to maximise conversion value while achieving a defined return on ad spend ratio. This is the primary strategy for e-commerce campaigns where each conversion has a dynamic revenue value (passed to Google via conversion tracking). Target ROAS requires robust conversion value data and is generally more demanding than Target CPA in terms of data volume requirements — many practitioners recommend 50+ conversions per month as a minimum, with higher volume preferred for stability.
Maximise Conversion Value
Similar to Maximise Conversions but focused on total conversion value rather than volume. It will prioritise higher-value conversions over lower-value ones if your conversion tracking assigns different values to different actions. Appropriate for e-commerce or businesses with multiple conversion types of different value.
Enhanced CPC (ECPC)
Enhanced CPC is a modifier applied on top of manual bidding. Google automatically adjusts your manual bids upward or downward based on the probability of conversion — raising bids in auctions likely to convert and lowering them for auctions less likely to do so. It provides a middle ground between full manual control and full automated bidding. ECPC is appropriate for advertisers who want to maintain bid control with a modest layer of automation.
Choosing the Right Strategy Based on Account Maturity
| Account Stage | Recommended Strategy | Reason |
|---|---|---|
| New campaign, no conversion data | Maximise Clicks or Manual CPC | Build traffic and gather initial data |
| 10–30 conversions per month | Maximise Conversions | Begin giving algorithm conversion signal without a hard CPA constraint |
| 30–50+ conversions per month | Target CPA | Sufficient data for CPA optimisation to stabilise |
| E-commerce with revenue tracking | Target ROAS or Maximise Conversion Value | Optimises for revenue, not just volume |
| Brand protection | Target Impression Share | Maintains visibility on branded queries |
Transitioning Between Bidding Strategies
Switching bidding strategies resets the learning phase — the period during which the algorithm recalibrates to the new objective. Expect temporary performance fluctuation for one to two weeks after any strategy change. Avoid making other significant changes (budget, audience, creative) simultaneously during a strategy transition, as it makes diagnosing the cause of performance shifts difficult.
When setting a Target CPA for the first time, base it on your actual historical average CPA rather than your aspirational target. Setting a CPA target significantly below historical performance restricts the algorithm’s ability to enter auctions and causes under-delivery. Gradually lower the target over time as performance improves.
Track the Impact of Bidding Changes
Changes to bidding strategy should be tracked with consistent UTM parameters so you can isolate the impact in your analytics platform separate from Google’s own reporting.
All parameter values are URL-encoded automatically. Spaces become %20. Use underscores for readability in reports.
Use the tool above to keep campaign URLs tagged before any strategy changes go live. For broader context on how Google Ads accounts are professionally structured and managed, read our guide on Google Ads management services. If you are evaluating whether your campaigns need professional management, see our comparison of PPC agency vs in-house team. Our digital marketing services page explains how Nexsage approaches bidding strategy decisions as part of full account management.
Chat on WhatsAppFrequently asked questions
Which Google Ads bidding strategy is best for beginners?
Maximise Clicks is the simplest starting point for new campaigns — it requires no conversion data and focuses on generating traffic within your budget. Once conversion tracking is set up and conversions are accumulating, switch to Maximise Conversions, then to Target CPA once you have 30 or more conversions per month.
How long does the Google Ads learning phase last?
The learning phase typically lasts one to two weeks after a bidding strategy change, significant budget adjustment, or audience modification. During this period, performance may be volatile. Avoid making further changes until the learning phase completes, as each change resets it.
Can I use Target CPA on a new campaign with no data?
You can set Target CPA from the start, but the algorithm will have no conversion history to learn from and will produce unpredictable results. It is generally more effective to run Maximise Conversions first, accumulate 30–50 conversions, and then switch to Target CPA with a target based on your actual observed CPA during the Maximise Conversions phase.
What is the difference between Target CPA and Target ROAS?
Target CPA optimises for a defined cost per conversion event regardless of that conversion’s value. Target ROAS optimises for a ratio of revenue to ad spend, maximising the value of conversions rather than just their number. Use Target CPA for lead generation where conversions have similar value; use Target ROAS for e-commerce where each transaction has a tracked revenue value.
Does increasing my budget help my bidding strategy perform better?
Budget constraints can limit automated bidding strategies. If your campaign is regularly hitting its daily budget cap, the algorithm cannot enter all eligible auctions and performance is throttled. Increasing budget in this situation can improve results. However, if performance is poor due to a misaligned CPA target or insufficient data, increasing budget will amplify the inefficiency rather than fix it.