Which of the following best describes the conversion rate?

The selected answer Number of impressions divided by the number of purchases is correct because the conversion rate is typically defined as the ratio of the number of impressions (how many times an ad was shown) to the number of purchases (how many times the product was bought as a result of the ad). This metric helps advertisers understand how effective their ad is at converting viewers into actual customers. A higher conversion rate indicates that the ad is successfully driving purchases, while a lower rate may suggest that the ad needs optimization in terms of targeting, creative, or call-to-action. The other options do not correctly describe conversion rate, as they involve different metrics like clicks or subscribe and saves, which are not directly linked to purchase conversion.