I have been a member of Plug In Vegas for several months now. I found out about them through an on-line at at Face Book advertisement. At the time they were offering a $7 month for up to four tickets. The agreement is that that price will not go up if you stay a current member.
It appears Plug in Vegas is a very small operation. The lady in charge works really hard in offering unique shows and events. My wife and I attended a few VIP parties at the Grand Casino Pool last year along with a few other events. Plug In Vegas wins a lot of points with me for being the only free ticket site to get tickets to The Script at the Cosmopolitan.
A lot of the events they get are for a younger crowed. They get a ton of night clubs and other party things. I'm probably going to stay a member for at least the next two years to see how things turn out. They are nearly as successful as their main competitors but have a nice niche. Their Face Book page is also pretty good.