Yep, I've run quite a few Adoption/Capture center games, by either owning or working at them... Let's see.
I currently co-own the Pokezoo Adoption Center, Pokezoo Battle Tower, Goldenrod Tower, Buena's Radio Show, and Crystal Caves Battle Arena... I work at the Crystal Caves Capture Center. I also owned a semi-successful adoption center back when anyone could make one, but it came in fourth in a vote to see which three adoption centers stayed =(. I don't remember much of it, so I won't comment on it.
Hmm... from easiest to hardest:
Pokezoo Adoption Center: This is easy to do because coming up with Pokemon isn't that hard, and there isn't much activity (at least not now, though I didn't feel that way a year and a half ago when I was the only only one working there). I got this job because I used to work at/own it, and then Steve, Amy, and Gabi let me co-own it when we restarted it recently.
Crystal Caves Battle Arena: So easy because it's so inactive and I hardly have to do anything yet... I work here because I'm friends with Matt, who let me be a co-owner of this part of CC.
Crystal Caves Capture Center: Not too hard because I like deciding people's fate... And it's often quite funny XD. I work here because Matt and Frank hired me because I'm thier friend.
Pokezoo Battle Tower: This is a bit annoying because it's so tedious often... And it's damn complicated when people use tons of status-changing things *glances at Steve and Amy*. I own this because Steve, Amy, Gabi, and I restarted it a few months ago.
Goldenrod Tower: This is really easy except for the Guess This's, which are very annoying when asked for in massive quantities. I own the GT because Quick hired me when he owned it, and then he left, leaving it to the employees.
Buena's Radio Show: Eh, thinking of questions gets annoying after a while, but it's still fun, and I can earn lots of stamps myself. I own this because Jay hired me, then left, so Frank, Faithless, and I took over as co-owners... Then Faithless quit and Jay came back, so he became the third co-owner.
And the scariest thing is that I devote more time to playing these games and other Adopted/Captured Pokemon ones, and talking to other people who do on AIM, than I do working at them XD.