How YouTube Got Viral

Play buttons and YouTube's interface - (37signals):

"YouTube co-founder Jawed Karim on How YouTube Got Viral.

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

Re: #4, the external video player did have an amazing impact. In a matter of months, YouTube seemed to go from nowhere to everywhere due to that slick and easy to embed player."