What is attach rate?

Attach rate refers to the ratio between the number of complementary goods or services sold relative to every primary product sold.

For example, the sale of protective cases for mobile phones relative to the mobile phones sold, or the sale of travel insurance relative to the number of flights booked with an airline.

This term is relevant in the financial world and helps measure the effectiveness of cross-selling strategies. It is important to understand the context, such as market conditions and business strategies, to correctly interpret the attach rate.