what zensiq is saying is basically correct. after you start uploading a certain volume of videos across several accts all with the same url in the description, the accts will start getting disabled automatically 20-30 minutes after upload. If this happens, you can just omit the url and edit the description an hour after upload.
Ideally, you could never put the url in the description and avoid detection, but clicks on the link account for about 60% of my traffic, so I'd rather risk the occasional mass-banning.
Another alternative is just to upload 20-50 videos across 10-20 accounts and then buy a new domain (i hate the tinyurl, as it looks more spammy and gets lower ctr.) and start over. I know a guy who actually did this on a regular basis and sold his old domains for a very good profit.