You may be wondering why so many apps like Tinder want access to your contact list. The last thing you may want is the app to send them marketing messages. But it turns out this is a very common practice to ask for access to contacts.
Most apps like Tinder want to access you contact list so they can build out their database of users. The goal is to expand their customer base by finding new people who may be interested in their product. You can choose to deny access on your device. However, doing so may limit the functionality of some apps.
Some apps even give you incentives for you to reach out to your contacts and invite them to join the app. Then they can then reach out to those users directly via email, text message, or other means.
Apps can also use the information about your friends to learn more about you. They can look into your social media accounts and find out things like where you go to school, your favorite sports team, etc.