I probably have 10 cards, and have had some of them for almost 20 years. One has a limit of 1/25 of another one. I'm keeping them as long as I can to keep my average credit age long.
Okay, then my next question is where do you keep all of these cards and how do you keep them safe?
I have 7 or 8 cards. None of them have a fee. I have a spreadsheet with their limits, interest rate, etc.
I keep three in my wallet. I note on them with a sharpie where to use them, which is where they get (the best) rewards.
The rest are in a desk drawer - with my credit card account papers, boxes of checks and old check book registers.
I have a magazine subscription on two of them and Angies List on another - so they get used once a year. Which reminds me to cancel Angies List as I haven't used it in years.
I'm refinancing my mortgage and the bank officer said I have the best credit he's seen in years. I was concerned because I haven't made a loan payment other than mortgage in many years.
To keep them safe... I don't let them go to seedy bars w/o me.