content: Digging into their "research" shows they are usually paid for by eHarmony or others like them and are basic surveys showing really very little difference (for example, one showed 6% online split up versus 7.6% offline while satisfaction was 5.84 vs 5.64).  Another big one was simulation of thousands of societies but simulations of this sort have their own preconceived biases.    The reality is that if online dating does lead to better relationships it is because of self-selection.  People who are looking for a long term relationship on these things are exposed to more people than they meet IRL and have a greater chance of meeting someone more similar to themselves.  The fact that studies have also shown that people who meet online and get married usually do so more quickly than people who meet irl first show that to be the main possibility.    As far as the infidelity part, that is because nobody really studies it (eHarmony and Tinder aren't going to advertise that kind of thing or pay for it) and if they did few are going to answer truthfully.  I know the only woman I ever fucked from a dating site was married at the time and that is all she wanted from the site.