I've received several calls from this number in the last few months.  I answered today to see if I could get them to leave me alone.  The woman at the other end told me that she's Michelle on a recorded line.  I said "Who is this" and she said that she's from some sort of DDS or DDF (really hard to understand the company name) and that she was calling me to see if I'd like to participate in a brief survey for the opportunity win $5000.  She then told me she could transfer me if I was interested.  I told her "no thank you" and hung up.