I rejoined FillASeat/Seat Junky a few months ago, and so far I'm very disappointed with the service. When I initially signed up about 2 years ago there were many events and the offerings were being updated quite frequently. So far, there seems to be maybe less than 10 events total that have booked up very quickly. I haven't been able to find an event that was available and was of interest. This program is a good idea, but so far I've been greatly disappointed this go-around. Unless their offerings get better, I would not recommend the service and will not renew again.
Update (10/25/17):
A month has passed since I reviewed SeatJunky. Offerings are very slim to nil (improv comedy shows and an event at the symphony.) This program continues to be a pathetic joke. DO NOT SUBSCRIBE TO THIS PROGRAM!
Update (6/19/18):
I have 5 days left of my membership, and I have not attended a single event. I've periodically checked the site and never found an event that was appealing or available. This service/site is a joke. DON'T WASTE YOUR MONEY!!!