A few weeks ago I was on a panel with Sam Yagan, CEO of OkCupid. Sam mentioned the new Red Light, Green Light feature they implemented recently. People with a red light on their profile tend not to reply, those with a green light, do. PlentyOfFish, on the other hand, lets people set specific criteria for what emails make it into their inbox- not looking for sex, no drugs, must not have kids, etc.
I’m a big fan of moderating communication and creating some controls for people to take advantage of. I think for the most part this is for women who are for example 39 and receive emails from 55 year old men who have no sense of age-appropriateness. I can’t see men filtering women as much, it’s difficult enough to stand out from the crowd.