StumbleUpon is an online community where users discover and rate web pages,
websites, images and video content. It acts as a personalised recommendation
engine using peer-voting and social networking principles.
Prediction:
Prediction aims to predict trends by asking the community to submit ideas and
vote for them.
Examples include Yahoo! Buzz (www.yahoo.com/buzz), Ramussen Markets
and Media Predict (www.mediapredict.com).
On Media Predict, users bet on media trends such as TV viewership and books
that are likely to sell well. Media Predict can generate predictions as to what
will and what won’t succeed; essentially helping media companies understand
what consumers really want.