I dont understand this. If I have 20-30 web 2.0 properties, I obviously want to build whatever links to them (Article directories, comments, etc.) But I see people will do things such as create web 2.0 profiles to that 1st tier, then backlink those web 2.0 profiles. Why do people do this? Why not just blast the crap out of your 1st tier so they get that link juice?