Videos on your site don’t have a direct influence on search engines.
Indirectly though, videos can help your search engine optimization by increasing the amount of time an end user spends on your site.
Google sees the longer time spent on your site as a good end user experience and a good indication that it should send more people to your site.
When adding video you should first make sure that the videos are relevant to your topic, engaging, and informative (or entertaining).
Negatives:
Having a video that is slow to load and boring could have the exact opposite effect on your rankings.
If your video is set to auto play it could annoy people.
If the video is added to the site incorrectly it could be extremely slow to load and cause people on poor connections issues with even bringing your site up in the first place.
Don’t forget all the internet connected phones either. iPhones and iPads don’t play flash video – if you don’t have text to go with the video you could be abandoning all that traffic.
In closing – Video can be a great addition to your site and help tip the scales in your favor as long as it’s done correctly.
Have direct experience with adding video your to site? Let us know in the comments or on our facebook page: http://www.facebook.com/pages/South-Jersey-Search-Engine-Optimization/