(I have this in my user info, but I wanted to also make it a bit more visible.)
If you add me and do not introduce yourself with a comment on a public post, even if you're positive I know who you are, I will probably not add you back. Introducing yourself is no guarantee, I will admit, but it has been known to help. This includes if we've met at a party recently, as I have been known to space on names, especially those only given once. If you drop me and I reciprocated the add, there's a better than 95% chance I'll drop you back, just to keep the list down to a duller roar. Telling me you wish to keep up with my locked material at a more leisurely pace can affect my decision. Also, I see the 300+ souls listed below as a reading list. And I don't read all of the books I buy all at once, so I can't read all journals at all times, either. I like to try, though. I used to keep up, but my job situation changed to something that keeps me busy.