This is how I get PR3s quite easily. Just takes some time. In one word: treat your video as a blog:

1- Most important thing I guess are LINKS. So I do all the usual web 2.0 stuff for each video.

Then go to google and find the first videos that appear in their listitngs for a keyword you're targeting and try to post a video response to it ( or just search YT for them ).

Then link from existing lenses, hubs or whatever you have ( if you care that much for that video. If not, don't drain your PR and leave it at that )

Finally, go to pingoat and ping your feed. Youtube feeds are not video specific that I know of. So, either open specific accounts for each product ( preferred ) or you can do some tricks including weird keywords in your tags and submitting the feed for that keyword, but I wouldn't go that route. Your feeds will start to get caught by other sites quite quickly, particularly for some keywords.

Youtube user feeds are in the form: http://www.youtube.com/rss/user/[insert username here]/videos.rss

2- Include your keywords in title, preferably at the begining. Even better ( though I have no scientific proof of this ), do it twice.

3- Treat your info as an article. First put a link to a redirecting info domain with something like "CLICK HERE FOR MORE INFO ON ...". Below, include ideally a unique article or just use some PLR and change it a little at the begining and end, or do some spinning trick. Whatever fancies you.

4- Comments are good targeted renewing content. Enough said.

5- The tags you include will determine other videos that link to you. Dont be shy and be wise when selecting them.

All of this is WH. There are MANY more tricks both WH and BH, but this has proven to be effective for me. Good luck