Though the sites may not encourage members to cheat on their partners, they do assist those who wish to do so, and have become very successful in the process.
While these sites do attract criticism, they also keep things up front among those who use them.
However, the truth is that many attached and even married people are also using the internet as a way to meet new people and to develop relationships.
Sometimes they are seeking only friendship, but more often than not, they are indulging in extra-marital affairs and infidelity.
It's also pretty dangerous when both parties have different levels of power within the relationship, as well as being really skeevy if the dude is married (and a lot of them are). Tinder is an online dating app based entirely on whether you'd bone the other person.