I have learned that after all the credit problems, the Great Recession, and the mortgage crisis unless if is negatively affecting your credit just leave it open. If you leave it open long enough with no activity and no communication from you they will likely close it in several years from now.
I opened a gas card when I was in college to build credit as I had one credit card. I used the card once a month in college, but once I graduated and got other cards I used those due to cash back/rewards programs. I wasn't super attached to the card so I forgot to use it and eventually they closed my account.
Now I make sure that any card I have that I might not use as often get setup as my auto renewal card and my Netflix, Eztag and other random stuff gets charged there so it it's $15-75 charged monthly and is active.
I have (had) two 'store' cards besides the gas card. One is a clothing retailer I don't frequent very often. I just realized they closed the account two months ago when I was looking at my credit report earlier this month. It wasn't a high limit and I got the card again when I was young to build credit so not that big of a deal.
I have one store card left with Sears from an appliance purchase 3-4 years ago. I assume unless I make another purchase in a year or two they will close the account.
I guess what I'm saying is unless you need to close the account for some reason if the account goes dormant for however long they are likely to close your account for you. I think this looks better as you can get a longer age on your credit and you don't see a bunch of accounts opened and then closed a short while later. Don't know if that is the right philosophy, but it's what I am doing.
All the branded accounts (Amex, Discover, MasterCard, Visa), you can use for anything and keep open and active fairly easily. It's the store cards that give me trouble as they don't really promote brand loyalty anymore, so I don't have a problem with them closing my account. Unless I'm financing a large purchase at 0% interest I doubt I'll ever open another store credit account.