Programmatic
Win rate
Win rate is the percentage of bids a buyer submits that actually win the auction, calculated as auctions won divided by bids placed, multiplied by 100.
Win rate tells a buyer how competitive its bids are. If a DSP places 1,000,000 bids and wins 150,000 auctions, its win rate is 15%.
A low win rate can mean bids are too low relative to the floor or competition, bid shading is too aggressive, targeting is too narrow, or responses are arriving after the auction timeout. A very high win rate can mean the buyer is overpaying. Buyers balance win rate against price and outcome metrics; the bid landscape shows how win rate would change at different prices.
Sellers track the related metric of bid rate (how often a buyer bids at all) and win rate by buyer, which informs demand path optimization. Note that "winning" the auction does not always mean an ad was shown: the impression might fail to render, or be filtered as invalid traffic, so won impressions and billable impressions can differ.
Think of it like this
Win rate is like a salesperson's close rate: out of all the quotes sent, how many turned into signed jobs.
An example
A campaign bids on 4 million impressions and wins 600,000: a 15% win rate. Raising bids 10% lifts the win rate to 22% but also raises average CPM from US$2.00 to US$2.30.
Related terms
Bid landscape
A bid landscape is an estimate of how many impressions a buyer could win, and at what cost, at different bid prices for a given audience or inventory.
Bid shading
Bid shading is a technique DSPs use in first-price auctions to lower a bid automatically toward the price actually needed to win, so advertisers do not overpay.
DSP (demand-side platform)
A DSP (demand-side platform) is software that advertisers and agencies use to buy ad impressions automatically across many exchanges and publishers, deciding which impressions to bid on and how much.
Auction dynamics
Auction dynamics are the rules and behaviours that decide who wins programmatic ad auctions and at what price, including auction type, floors, fees, bid shading and bid order.
First-price auction
A first-price auction is an auction in which the highest bidder wins and pays exactly what they bid, which is now the standard model in programmatic advertising.