They keep trying to recruit me....?

The Army keeps trying to recruit me. They have mailed stuff, they have called me a couple of time, and they have even stopped by my house. The recruiters said they are doing this with everyone who just graduated from my high school. The thing is I asked about a quarter of the graduating class and none of them have gotten the phone calls or the visits to their house. Any idea why they seem to be trying so hard to recruit me even though I have told them I have no interest?