You can only intercept on the way if you look far ahead.
Publicly visible job openings are sifting through hundreds of resumes (especially in the economy), from spams by those who are very unsuitable for the position, while those undisclosed positions are often obtained by others through social circles.
The best marketing is content, the best content is product, and the best product is trust.
Because the key metric for measuring the success of an internet product is the number of active users and their level of engagement, if a large number of users are using your product to argue with and attack each other, they are still active—and as long as those metrics go up and revenue follows, moral standards can be set aside.
Services that hook users typically give them an identity, whether it's a real name or just a username. With that identity, users can gradually invest—time, energy, money—making it "valuable" through systems like reputation, levels, and points. Once vanity is satisfied, they keep coming back to nurture their virtual self, and retention climbs.
In anonymous apps, users have no identity to invest in, so there's no reason to return once the novelty fades.