Houseparty.com organizes "marketing parties" for a wide variety of companies. You can score some nice free stuff if this kind of thing interests you and you don't mind getting a lot of marketing email and postal mail.
That last statement is just an assumption from reading their privacy policy. I'll discuss their privacy policy more at the end of the article.
The whole idea behind their house party concept is to bribe the host with free stuff and bribe the guests usually with coupons and/or samples. Essentially, the host becomes a marketer to show off the companies goods. It's basically an organized and orchestrated viral marketing campaign.
You can visit the Houeparty.com site and browse the current house parties and see if any of the free stuff they are offing appeals to you. You can register for a specific house party or sign up for the mailing list to be notified of future free stuff events.
Now, about their privacy policy -- it is about the wimpiest privacy policy I have seen to date. They state that they will share your information with third parties. If you don't wish them to share your information you need to send them notice by mail or email. They state that it may take several weeks for them to comply with the request.
They further state, essentially, tough luck if they have already shared your information before processing your opt-out request. I realize they are a marketing company and really want to be able to share your information. However, not offering a simple opt-out option on their forms puts them on my "sleazy marketer" list. I highly recommend that you use a secondary email address instead of your primary address when registering.