This is an idea for a dating and personal networking site. When you visit you are greeted by a series of questions, such as “Are you male or female?” “Do you like rock or R&B?”. You keep answering questions until your profile is unique (your combination of answers is different from everyone else’s). At that point you enter your email and save your profile.
When someone else visits the site and answers a series of questions in the same way you have, you are sent an email. You are prompted to return to the site and enter a new question (and answer) that will restore your uniqueness.
At any point while answering questions you may browse people that have a similar or opposite profile to your own. Advertisers may inject questions like – “Do you like Coke or Pepsi?” They may also target ads based on your profile.
I was inspired by this idea by using sites like 43things.com and standpoint.com. These sites make it easy to create a personal profile by clicking links and voting “I want to do this” or “I believe this”.