ROAS

ROAS (Return On Ad Spend) is the ratio of revenue generated from an ad campaign to its cost. A ROAS of 4 means $4 in revenue for every $1 spent. Higher ROAS = more profitable campaign. For an eCommerce store, healthy ROAS is typically 3-5; ROAS under 2 usually indicates the campaign isn't profitable after additional costs (payment processing, shipping, returns).