The same way it could be done manually. You search for non promotional videos, slideshow presentations, audios you're allowed to embed. Create a secret category on your blog for borrowed content. Exclude it from the front page and table of contents on your website. You don't want all your visitors to see it. You'd better use it for driving traffic to your site distributing it in social media. You just need more valuable things to share there. So instead of sharing competitors' info published on their sites you share their content embedded on your site, you're not promoting others building their lists, making them sales, you promote yourself. You just make a new post that consists of somebody's relevant video (not modified, as is) and your form or ad or link to your own content or whatever (below it or in the sidebar). A minute of work. Then tweet it, G+ it, Stumble it, etc, etc, etc.
Make a lot of these posts, write tweets for them, schedule and drive traffic to your site 24 hours per day from Twitter, not this hour's for me, that's for a competitor.
As soon as a piece of borrowed content stops bringing you traffic from social media - delete it.
The reason I'm giving away this method - I want your opinion. I'm thinking of testing it but somehow I don't feel good about it. I'm not recommending anything, I'd love to know what you say. Thanks.
You just make a new post that consists of somebody's relevant video (not modified, as is) and your form or ad or link to your own content or whatever (below it or in the sidebar).