Wondering about copycat TV shows.

Have you ever noticed if a TV show is very successful you get a whole bunch of spin-offs or copycat shows?  This seems to happen in shows of all different themes but lately there has been an explosion in reality picker, pawn-shop, and storage auction shows.  The pawn shop shows all started with Pawn Stars located in Las Vegas, and now there is a Cajun Pawn Stars show from Louisiana,  Hard Core Pawn Show of the American Jewelry and Loan located on 8-Mile Road in Detroit, to name a few and other spin off shows that show restorations for these pawn stores.  The picker shows started with the American Pickers with Frank and Mike and now they even have the Canadian Pickers (Cash Cowboys), and a couple of girls out looking for junk to turn into art furniture or something.  Then there are the storage locker auctions.  I know of a few of them.  Now, what makes all these shows so popular?  My wife and I were sitting here watching one last night and I ask her why we enjoy these shows.  It seems that after a while you get to know the characters in the show and want to see what they are up to or you like to see what the junk that some people pawn or store is worth.  Hey, you never know, you may have a multi-million dollar piece of junk in that bottom drawer or sitting in a corner or hanging on the wall.  Now me, all my junk is worth billions and I am keeping it, so there!!! (grin)  Now, if I were smart, I could take all this junk, sell it, and finish my life being filthy rich.  Now that sounds like plan to me, what do you all think?