There are lots of Web 2.0 creation services on BHW, each claiming to build you strong, long-lasting links.
The reality is that most of the time you would be better off just throwing your cash in the bin.
1. The created Web 2.0 sites usually consist of poorly spun, unrelated articles, which will never pass a manual inspection.
2. The content quality is so awful that it is often not legible, relevant or likely to ever interest the googlebot.