What I do is basically sampling as an art form. It started with early Public Enemy and Beastie Boys albums and such. Copywrite laws were passed and that vanished from mainstream rap. It's done on an underground level now. It's also closely related to turntabling, which I do as well, but not on these mixes.
There was a fad a few years ago of something called bootlegging or mashups. Which was taking the vocals from one song and putting it over the music from another. That was kind of fun, but it only stays interesting for so long. It's deader than Ray Charles at this point. But bootlegging had a lot of people trying to be "cute" with it and mixing up stuff that you didn't usually see. Sampling was originally mainly done to other rap songs. I took some of that cute influence.
Sampling like this is not done on a commercial level because of copywrites. There are some exceptions, like Fatboy Slim has dabbled in it. It's market is clubs, where turntablists can use it like battle raps, and the internet has added a new dimension. People like you, who hear it somewhere and think it sounds neat, is a growing segment of the audience.