Search ads · also called AdWords, Google AdWords
Google Ads
Google Ads is Google's advertising platform, where businesses bid to show ads on Google Search, its search partner sites, YouTube and other properties.
Google Ads (called AdWords until 2018) is where the money in most search arbitrage begins. A business chooses keywords, writes ads and sets bids. When someone searches, an ad auction decides which ads appear, and the advertiser pays when the ad is clicked (PPC).
The crucial detail for arbitrage is where those ads can run. Besides Google's own results page, Search campaigns can extend to the search partner network: non-Google sites that show Google search ads. Google's help describes this as hundreds of non-Google websites plus YouTube. An arbitrageur's results page, fed by AdSense for Search, is one of those partner sites. So Google Ads is the demand side and AFS is the supply side of the same marketplace.
Arbitrageurs also meet Google Ads as buyers. Search-to-search operators purchase clicks through it, and Google Demand Gen and Performance Max campaigns are used as traffic sources, subject to Google Ads policies on misrepresentation and abuse of the ad network.
Advertisers' controls have grown: site-level search partner reporting, exclusions and credits for invalid clicks. Those controls shape how much a feed click is worth.
Think of it like this
Google Ads is the wholesale market where advertisers place their orders. Search partner sites are the extra stalls where those goods are also put on display.
Related terms
Search partner network
The search partner network is the collection of non-Google or non-Microsoft sites where an advertiser's search ads can appear through syndication.
AdSense for Search (AFS)
AdSense for Search is Google's programme that lets approved publishers show Google search and shopping ads on their own search results pages and share the revenue.
Ad auction
An ad auction is the instant, automated contest run for each search that decides which advertisers' ads appear, in what order and at what price per click.
PPC (pay per click)
PPC, or pay per click, is an advertising model in which the advertiser pays only when someone clicks the ad, not when it is merely shown.
Microsoft Advertising
Microsoft Advertising is Microsoft's ad platform, formerly Bing Ads, which sells search ads on Bing and on partner sites that syndicate its results.
Advertiser opt-out (search partners / parked domains)
Advertiser opt-out is an advertiser's ability to stop its search ads appearing on partner sites, and in 2025 to 2026 on parked domains, outside the search engine itself.
Sources: Google Ads Help: Search partners, definition, Google Ads Help: Search partner network (SPN) announcements, Google Ads Help: How the Google Ads auction works