Perhaps it was coincidence, or perhaps putting the right things in your profile tends to get you noticed?
I added people that I had interacted with at my previous companies as connections, I listed any articles I've written, put up links to personal projects/sites and reduced my skills to a small list of strong skills. I also joined a few small but known groups related to my work and made a couple of posts. Nothing too special, just a few posts here and there to answer some questions. Finally, I added my Stack Overflow reputation and any "out-of-work" stuff I handle. Basically, going from 30% completeness to 100% completeness on my profile.
A few days later I checked back on my profile and found that my profile views had gone from zero to around 10-15 a day. I tend to get a lot of recruiter spam on there but have had a few EMEA recruiters from Google, Microsoft and Facebook stop by my profile. No offers, but always nice to see people interested in reading about me.
What worries me is that recruiters must think that this is a legitimate way to source talent...