These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Cash Cow Franchise: As the most popular shows on the channel, they get quite a lot of merchandise.
The idea and official recognition of a DCLAU seems in part motivated to establish the DCLAU itself as a (Cash Cow) Franchise, much like the shared universes/franchises of the Marvel (now incidentally owned by Disney) and DC franchises (or alterantively, Disney's own "Princess" franchise).
The most popular shows seem to be especially emphasized with crossovers, so far with Jessie,Good Luck Charlie, Hannah Montana and the Suite Life series having the most tie-ins.
Friendly Fandoms: Both Austin & Ally and A.N.T. Farm are this to iCarly, despite being on rival networks, have a friendship based around the supporters of the three major canon relationships on the shows, Carly/Freddie, Austin/Ally, and Chyna/Fletcher, Three of them being examples of the Just Friends.
Hollywood Hype Machine: One of the most well known examples. As well as being on these shows, the actors also usually release an album and have a finale movie. Unfortunately, it rarely leads to lasting success outside of Disney (though that seems to be changing now, at least with Selena Gomez and Demi Lovato).
There's also a significant (typically male) older audience as well, ranging from late teens to well over typical college-age. Given what appeals to males in the first place, this can lead to some Unfortunate Implications.
Girl Meets World and I Didn't Do It are direct shots at the Periphery Demographic: the former brings with it tremendous nostalgia appeal thanks to Boy Meets World and its fans who are roughly the same age as Cory and Topanga themselves (and thus potentially have children of their own fitting into the DCLAU "target" demographic); while the latter is a more straightforward appeal towards a slightly skewed demographic with a cast and humor and scriptwriting thought to be more appealing to an older teen demographic.