There are a number of web services that will take your footage and help you sell them, but most of them will not take everything that you have. They usually have to approve the footage and they will often deny footage that is common. For example, you may have trouble selling video footage of Los Angeles beaches, yet will have better luck at a rare beach in a foreign country. The best way to balance this is to look at the footage you have and run it on keywords through the website you are thinking about using for distribution. If you do not get any similar footage then you may be looking good.