I can't speak for Patrick but I do keyword based landing pages on the main ___domain where the product is for sale so you can pass page rank from keyword pages to your product pages or TLD.

This is also less work because you can create these optimized topical landing pages programmatically and just add some unique keyword rich content to them.

Also if you are adding domains regularly just for content you will have to wait a decent amount of time to let the ___domain age and you are always starting over at PR0.