The other reason that it works so well is that if you submit your video to Youtube for example, then you will get a very quick and powerful ranking in Google
Keep in mind most outbound links on YouTube use the nofollow attribute rendering the link void of link popularity which means any link sitting on Youtube pointing to your site will drive traffic but nothing else.
I wrote this post recently, it addresses what's being talked about here:
Don't Use YouTube For Building YouLinks
As a link builder Iím not enamoured with YouTube and do not recommend using it as a primary way to build links or as an integral part of your SEO program.
Videos on YouTube are on YouTube so any optimization effort you implement helps YouTube and not your website/pages.
YouTube contributes to the pinking of the ĎNet/Web (uses nofollow) so any link you insert to guide people back to your site passes no link popularity.
While traffic from YouTube can be beneficial, you have to optimize the content on YouTube like any other in order for people to find it. This is time better spent elsewhere.
Efforts to make a video go viral begin with the webmaster, not YouTube
Itís doubtful youíll build a brand following on YouTube unless the public is already aware of your brand.
By-n-large people look for information on a search engine first, they donít search on YT for a place to buy baseball cards. There is a reason Google has become a verb and YouTube a pastime.
But the number one reason?
YouTube results bump web pages down in the general search results and web pages make sales , videos donít!
Want to see what I mean? Look here, here, and here and notice how the videos are all ranking in the top five but the sites they represent Ė donít. Yes the exposure is nice but where is there opportunity to make a sale?? Throw in local search results and images showing up and it can take a while to get to a static search result. If your goal is to make your website an authority in your industry/niche, you should house and promote the videos on your site, not YouTube. This will help with algorithmic authority, branding and traffic.
So is using YouTube to build SEO links a wasted effort? Pretty much which is why I donít recommend using it to increase your link popularity but I wouldnít totally discount using the number two search engine on the Net to build awareness. Consider doing this:
Make shorter versions of your videoís and insert on YouTube, longer vid stays on your site
Create those shorter versions as teasers and as a lead-in to promotions/information on your site
Be sure the start and ending frame of the vid include the URL to your website
Optimize your YouTube listing with your keywords
Be the first one to leave a comment/review under your vid, include the URL to your website and explain a longer more detailed version of the vid exists on your website
Encourage everyone you know to drop a comment/review on the video (re/views help push your vid to the top for your keywords)
Create a video area on your site just as you would a media room and promote it to the media, your customers, vendors etc.
Make the vidís on your website available through Creative Commons, make full descriptions embedded with kw rich links part of your attribution.
You need to decide whatís best for your site and if having YouTube videoís come up in the serps for your keywords is your goal, power to you. But if youíre in business to make a profit and plan to use video to attract links, know the links you point at YouTube will have little to no effect on your overall rankings.
Use YouTube or any image/audio hosting site wisely and they can be your greatest ally and not a ranking enemy.