YouTube was founded by Chad Hurley, Steve Chen and Jawed Karim, who were all early employees of PayPal. Hurley and Chen said that the original idea for YouTube was a video version of an online dating service, and had been influenced by the website "Hot or Not". They created posts on Craigslist asking attractive females to upload videos of themselves to YouTube in exchange of an $100 reward. Difficulty in finding enough dating videos led to a change of plans, with the site's founders deciding to accept uploads of any type of video. Karim said the inspiration for YouTube first came from Janet Jackson's role in the 2004 Super Bowl incident when her breast was exposed during her performance, and later from the 2004 Indian Ocean tsunami. Karim could not easily find video clips of either event online, which led to the idea of a video sharing site.
Because of the similarity of the names, some think that MP4 is the evolution of the already popular MP3 format. But in reality, these are very different technologies. MP3 (MPEG-2 Audio Layer 3) is an audio codec, while MP4 (MPEG-4 Part 14) is a single file standard used to simultaneously contain audio and video. It is very similar to the popular AVI but has the advantage of allowing the incorporation of subtitles. Bearing in mind that this format may be encoded, that encoding may have been done by different types of codecs. It is common to find devices on the market that are designated as being compatible with MP4, but this generally just means that such devices are able to read video, unlike MP3 compatible devices that only allow to read audio. This format results from the evolution of the also popular Quicktime format.