5400 backlinks would be awesome, especially for $20 a month. If it's credible than do it. Try looking for reviews on google. I am also interested in this program as a "sponsored publisher" if I decide to do it I will let you know how it goes.
Well you can also get it for free. You just have to add a link to the php file on your main page. I must say that these sort of sites scare me.
Most of those links would be garbage. You need to look at getting high quality links. 10 high quality links are a lot better than 5000 really crappy ones. Cheers
http://www.pagebowl.com for 1$ you get quality permanent ANTI-SPAM links and guests on your website. it has a special keyword program which will find the right users for you .