Okay, as usual, I'm very grateful for replies to my noobish type questions. Anyways, here it goes. I have learnt the value of linking to my site of course. But if I discover a nice treasure website that does not have NOFOLLOW for comments, what happens when they decide to switch to nofollow? I guess my question is, is this like switching a light on and off for them? Once they implement donotfollow, does that mean all previous posts with follow links will then automatically become do not follow? Further, when a website switches to do not follow, would they have to do that for each page or is it very simple for them to do for an entire site? Something that I can't really pinpoint from googling this on my own. Any thoughts appreciated.
Assuming its wordpress you can turn every old comment and post to nofollow with one click really, and all those old links immediately stop counting for anything.
When you make the blog nofollow the links will no longer count in google but they will still count in other search engine.