The page they are referring to is offering a backlink.
And "get backlinks" is an over-simplified answer that offers no real help. Just getting backlinks won't do much for any website. You need to get high quality on-topic backlinks. Getting these isn't as simple as "just going out and getting them". You have to attract these links somehow and high quality unique content will do just that.
sure will .. its the same niche .. targeted same stuff you're promoting .. get some with higher PR's =)
It won't. That site is just an ad site. It has no relevance to anything and links on it will be worthless. And the fact that is has so many links on it means it will pass extremely little PR. And PR all by itself is worthless. It needs to be associated with a relevant page, and preferable a high quality one at that, to be meaningful.
Submitting to a site like that is done on the off change it gets famous and gets lots of traffic. That site will not get famous.