ROAS (return on ad spend) and ROI (return on investment) are both measures of the efficiency and effectiveness of an investment. However, they differ in the specific type of investment that they are used to evaluate.
ROAS is a measure of the return on an advertising investment. It is calculated by dividing the revenue generated from an advertising campaign by the amount of money spent on the campaign. For example, if you spend $100 on an advertising campaign and it generates $500 in revenue, your ROAS would be 500/100 = 5.
ROI, on the other hand, is a measure of the return on any investment. It is calculated by dividing the profit generated by an investment by the amount of money invested. For example, if you invest $100 in a stock and it generates a profit of $50, your ROI would be 50/100 = 0.5, or 50%.
In summary, ROAS measures the efficiency of an advertising campaign, while ROI measures the efficiency of any investment.