My LinkedIn policy for connecting

I often get requests to connect from recruiters, etc., which I appreciate.
However, this is my policy and the email I send them:

Thanks, but I make it a rule (99% of the time anyway) to only connect with people I actually know / have met.

Exceptions:

1. I really respect your work (or your admiration for me), or you're really cool
   
2. Our interests or friends are so similar I can't believe we haven't met yet, but we should!
   
3. We have exchanged email a few times or transacted in other ways (which means really that we "know" each other)
   
4. Our networks are so dissimilar or disconnected that we should connect them for some kind of multi-disciplinary cross-pollination possible synergisms
   
   
5. For networking possiblities (I guess similar to 4)
   
6. For the right amount of money (hey--everyone has their price)