Well, there are some points:- 1. Make Title of your Video keyword rich ( what a visitor will type to seach that kind of videos) 2. Tag your videos with keywords. 3. Write description a small info about the video Good luck!!
You need to create good content and target competitive search terms and promote the url, if it has viral element wihin shorter time it get popularize.
Popularity of a youtube video is based mostly on it's content. Making a youtube video promoting your business probably won't get very popular as about 98% of the youtube userbase won't care who you are or what you do. Video's that do well are those that are informative (relating to current popular topics such as elections, global warming/environment, apple products), funny, or film/gaming realted (previews etc). Your only real chance is to just bung your URL on the video and hope for the best. There are much more streamlined methods of attracting your target audience though.
Does it depend on what the search is? i.e by ranking, date, most views etc. or are you meaning in the natural search results?
As the above points are necessary but quality of the video should also be best which is the most important factor. A video should not be common or general, make it somewhat unique or delicious for visitors.