This number has appeared on my caller ID a lot recently, though I have never been home to answer the phone.
Some telemarketing companies use autodialers to call you, often multiple times a day. When you answer the phone, all you get is a hang up. The autodialer then logs when you answered the phone, versus when you didn't answer the phone. This information allows an actual human telemarketer to call you when you are actually home.
For instance, if you see the number appearing on your caller ID all day, but you aren't home to actually answer the phone, the human telemarketers aren't prompted to call you during those times. If, however, you answer the phone, it gets logged in the system that this is a good time for a human telemarketer to call you in the future because you are likely home.
Not sure if this is the case here, but it sounds like it...