If I had a 1,000 twelve month interest free loan, by the time I paid it off, I'd have at least $1,050 from investing (bare minimum crappy investing mind you) leaving me with $50 profit. If I had 100k interest free loan for 12 months... oh damn, I'd definitely cash in, probably in real estate.
That being said, some people don't have the know-how or desire to invest money properly and tend to rack up CC bills without ever paying them off, which ends up hurting credit scores, etc. so they play it super safe and never want to owe money.
Those who take the risks become rich, and when you don't have your own money to make money with... you use others.
NOW, for hifi's situation where it's a money strapped situation and not an investment situation... yea, opening up CC's might not be the best idea in the world. You can only take out so much credit. Mortgage + Car loan + every CC adds up.
..... UF investing club anyone?
No it wasn't that we were strapped exactly. We have the money, but didn't really want to pay cash from pocket/ take it out of the savings. The card was 12 months same as cash and thats the only time we use cards like that is on specials for bigger purchases. We also always pay them off by the 11th month.