Bidding and Budgeting
Choosing a bid strategy
Strategies differ in who sets the bid. Manual CPC and Maximize clicks focus on traffic. Smart Bidding uses auction-time signals such as device, location, time, query, and audience to optimize for conversions or value. Core options are Maximize conversions, Maximize conversion value, Target CPA, and Target ROAS. Target impression share is a share goal, not a conversion goal.
Requirements and traps
- Target CPA and Target ROAS need conversion tracking with enough recent history; Target ROAS requires conversion values passed in the tag.
- Switching strategies or making large budget and target changes restarts the learning period, so results look unstable for several days.
- Daily budget is an average. Campaigns may spend up to twice the daily budget on a given day, but not more than daily budget × 30.4 in a month - questions often reverse this rule.
- Shared budgets pool spend and can shift money between campaigns.
- Portfolio strategies apply one target across campaigns with similar goals.
- With Smart Bidding, device and location bid adjustments are largely replaced by signals, so questions about tuning device bids usually point to Manual CPC.
Rule of thumb: change one lever at a time. If spend is capped, raise budget before loosening a target CPA.
Worked example: a $50 daily budget may spend up to $100 on a high-demand day, provided the month stays within roughly $1,520 ($50 × 30.4).