I get this on a semi-regular basis from Stack Overflow. For a while, I removed my contact information from my profile to limit the amount of noise I received. Now that I'm an employee I'm actually paid to receive it, some of it is actually useful.

Some folks want to round out their online footprint through their tracked relationships (Twitter, Linkedin, etc) - so they seek out people that seem (1) likely to have connections and (2) interesting, withing their fields of endeavor -- for more or less modern day 'pen pals.' and follower / presence 'piggy backing'.

I wouldn't read too much into it.