ROAS or return on ad spend is an important revenue-based mobile app KPI. It measures the effectiveness of app advertising campaigns by measuring the revenue generated for each dollar spent on advertising.
To calculate ROAS, divide the amount of revenue generated by a certain ad campaign by the cost of that ad campaign.

Let’s say an ad campaign brought in $6,000 after spending $1,200 on ads. That’s a $4,800 profit or a 400% return on investment. Put simply, for every dollar spent on advertising, four dollars were earned in revenue.
To increase your return on ad spend, consider using engaging ad formats like rewarded video ads, offerwall ads, and playable ads.