Why is my CPC lower than my base bid?
Last updated: October 2, 2025
If you notice that your Cost Per Click (CPC) is lower than your base bid, this is actually normal behavior due to how our auction system works. Here's what's happening:
How the Auction System Works
Our platform uses a second-price auction model, which means:
Your base bid represents the maximum amount you're willing to pay per click
You only pay $0.01 more than the next highest bidder, not your full base bid amount
This helps you stay competitive while keeping costs as low as possible
Example Scenario
Let's say you have a base bid of $0.40:
Your base bid = $0.40 (maximum you're willing to pay)
Next competitor's bid = $0.18
Auction result = You win and pay $0.19 CPC ($0.01 above the competitor)
Even though your base bid was $0.40, you only paid $0.19 because that's all that was needed to win the auction.
Understanding Minimum Bid Settings
The minimum bid setting (such as $0.40) in your campaign setup refers to:
The minimum base bid you're allowed to set before any multipliers are applied
Your maximum willingness to pay per auction
Not the minimum amount you'll actually pay
This minimum bid requirement ensures you're competitive in auctions, but the second-price auction logic means you'll often pay less than this amount.
Auto Bid
Auto Bid works by automatically adjusting bids for advertisers rather than using fixed manual bids.
The lowest bid returned by RTBA is the price floor itselfÂ
No price floor