Buying traffic · also called bidding strategy
Bid strategy
A bid strategy is the rule an advertiser gives an ad platform for how much to pay in each auction, from a fixed manual bid to fully automated goals.
Every time an ad could be shown, an auction decides who wins and at what price. The bid strategy tells the platform how to behave in those auctions on your behalf.
There are three broad families. Manual bidding sets a price per click and leaves it. Volume strategies (Meta calls its default "lowest cost") spend the whole budget to get as many results as possible with no price guarantee. Goal strategies add a constraint: an average cost per result (cost cap, Target CPA), a hard ceiling per auction (bid cap), or a required return (Target ROAS).
In search arbitrage the choice is really a statement about margin. The buyer knows roughly what a visitor earns (RPV), so the bid strategy must keep the cost of a visitor below that figure. Volume strategies scale fast but can overpay; caps protect margin but may leave budget unspent. Whatever the choice, the platform can only hit a target if it receives accurate, timely conversions through a postback or Conversions API.
Think of it like this
At an auction house you can shout your own bids, or brief an agent: "buy as many as you can", "never pay more than 20", or "average 15 across the day".
Related terms
Cost cap
A cost cap is a bid strategy, best known on Meta, asking the platform for as many results as possible while keeping average cost per result near a set amount.
Target CPA (tCPA)
Target CPA is an automated bid strategy where the platform sets bids to win as many conversions as possible at an average cost you specify.
Target ROAS (tROAS)
Target ROAS is an automated bid strategy that sets bids to reach a chosen ratio of conversion value to ad spend, such as $1.30 back for every $1 spent.
Value-based bidding
Value-based bidding is automated bidding that aims for the highest total conversion value, not the highest number of conversions, using values the advertiser reports.
Learning phase
The learning phase is the early period after launching or significantly editing a campaign, when the platform's algorithm is still testing who to show the ad to.
Maximum CPC bid
A maximum CPC bid is the most an advertiser is willing to pay for one click on its ad; the actual price charged is often lower.
Sources: Meta for Developers: Bid strategies