How did they do it?
The secret, according to a recent speech given by Jawed Karim, one of the founders, is that they built the following four aspects into their application:
1) related video recommendations
2) one-click emailing to spam a friend about a video
3) more social networking and user interaction tools like video comments
4) an external video player.
The lesson here for any marketers and many a Web 2.0 entrepreneur is that viral marketing works if you're smart, strategic, and lucky.
You can listen to the full speech on, where else, YouTube.
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