I can tell you all, that by experience it doesn't gain you anything. Doesn't hurt to try, and I felt that if someone was compelled to follow me, I followed them back. I already know the people that are highly interesting to me and I check their blogs regularly. My feed is however highly interesting and I wouldn't otherwise be able to see such unusual blogs without it.

If you asked me if I would do it all over again. The answer is no because I don't think it is worth the time.