About Secondary Characters and Being Lazy

     Halloween is over... it's time to get ready for Christmas!!! Seriously. It's never too soon.
     Anyway, there's something I've been wondering about so I thought I'd put a question out to the blogosphere. In my WIP I have a lot of characters. Of course, when you have a lot, most are secondary. My question is, how much do you develop a secondary character? I feel like I use them for my purposes- they appear to do what I need them to do, and then disappear when I don't want them around anymore. It is my story and I can do what I want, but I'm wondering if it will end up too contrived. So then I'm thinking, I need to add a scene with this character or that character because I've kind of forgotten about them lately and they haven't been around in awhile. But then am I just adding unnecessary stuff? So how much do you develop secondary characters? Is it okay if they are only around here and there?
     30 Day Song Challenge, Day 25: A Song That Makes Me Laugh
     I don't usually laugh- at least not out loud- to most songs. Let's face it, songs aren't usually that funny. Or maybe I just don't listen to the funny ones. Anyway, this is the only one I could think of.
The Lazy Song by Bruno Mars