Colleges contacting me?

So I'm getting a bunch of letters and e-mails from colleges asking me to consider them during the applying process. I know this happens to a lot of students right after they register for Collegeboard (PSAT, SAT, etc). I got letters from some Ivy League and other great schools, (Harvard, Yale, Princeton, Columbia, Boston, Penn, Dartmouth, Brown, Georgetown, Cornell, Standford, NYU, Rice, Colgate etc). I know these are great schools that are competitive and won't send letters to just anyone. My friends, who haven't gotten letters from these schools say I'm just getting them because Collegeboard knows my address, but I think otherwise. Why would they call me a "prospective student" with "outstanding achievement" if they wouldn't be interested in me. After all, aren't they mostly sending letters for students they're interested in? If not, they would be wasting their time and money. So, are these schools interested in me, or are they just sending me letters for the heck of it. Be honest! ;)