Smart Bidding
Google Ads' suite of automated bidding strategies that use machine learning to optimize bids in real time for each auction, including Target CPA, Target ROAS, Maximize Conversions, and Maximize Conversion Value.
How Does Smart Bidding Work?
Smart Bidding uses Google’s machine learning to set bids for each auction in real time, analyzing hundreds of signals that manual bidding cannot process. These signals include device type, location, time of day, operating system, browser, language, remarketing list membership, ad creative, search query context, and demographic data. For each auction, Smart Bidding predicts the probability of conversion and sets a bid that maximizes the chosen objective within the advertiser’s constraints. The system learns from conversion data over time, becoming more accurate as it accumulates performance history. Google recommends at least 30 conversions in the past 30 days for Smart Bidding to perform effectively.
What Are the Smart Bidding Strategy Options?
Google offers four primary Smart Bidding strategies. Maximize Conversions sets bids to get the most conversions within the campaign budget — best for campaigns focused on volume without a specific CPA target. Target CPA sets bids to achieve conversions at a specified average cost per acquisition — best for campaigns with a defined CPA goal and sufficient historical data. Maximize Conversion Value optimizes for total conversion value within budget — best for e-commerce campaigns where different conversions have different values. Target ROAS sets bids to achieve a target return on ad spend — best for e-commerce campaigns with a specific profitability goal. Each strategy requires different levels of conversion data to perform optimally.
When Should You Use Smart Bidding vs Manual Bidding?
Smart Bidding outperforms manual bidding in most scenarios, particularly for accounts with sufficient conversion data and campaigns running across multiple devices and locations. Manual CPC bidding still has use cases: new campaigns with minimal conversion history (Smart Bidding needs data to learn), highly specific keyword strategies where bid-level control is essential, and accounts where business constraints require predictable spend patterns. A common transition strategy is to start new campaigns with manual bidding, accumulate 30+ conversions, then switch to Smart Bidding once the algorithm has enough data to optimize effectively.
How Do Third-Party AI Tools Work with Smart Bidding?
Smart Bidding handles bid optimization within Google Ads but cannot coordinate across platforms. Third-party AI tools like Leo work at a layer above Smart Bidding — managing campaign structure, keyword strategy, creative, and budget allocation across Google, Meta, and LinkedIn while letting each platform’s native bidding system handle auction-level optimization. Leo sets the Smart Bidding strategy and target CPA/ROAS based on cross-platform performance analysis, then monitors results to adjust targets over time. This layered approach combines Google’s auction-level intelligence with cross-platform strategic optimization.