edit: I see others have mentioned rewards programs - in my not so humble - not worth a pinch of the proverbial. After years of using CCs for everything - I once even brought a second hand car on a CC, I think I have enough points to get a tea towel or can opener. I just got a statement from bank pointing out I'll start to LOOSE 1,000 every 3 months or something. And I'm with the really nice bank.
Once you're cracking 100,000 amex MR points that's a 1 way first class ticket from Mel-London.
Now if you were #ballin' and buying fancy cars on such a CC, you'd be easily able to rack up a few hundred thousand MR points. Free first class trips ain't such a bad perk, yaknow.
Plenty of small business owners use company CC's to generate miles/points and then its free travel time.