The ratio of the amount of revenue generated by an ad campaign to its cost. If you generated $10,000 from a campaign that cost $1,000, your return on ad spend (ROAS) would be 10:1. While similar to return on investment (ROI), ROAS is more focused on the hard cost of a campaign rather than on the overall value of running a campaign, which could include brand awareness or other marketing goals.
A company spends $1,000 on an online advertising campaign and generates $5,000 in revenue directly attributed to the ads.