Depending on how you value «free» will depend on how much each rewards point or airline mile is worth to you. (thepointsguide.com)
I've seen people who weren't bad at their job and didn't hate their job, but their position didn't fit their talents or provide as much reward as it could. (realtormag.realtor.org)
You don't have to invest much at all and get so much reward. (adulthookups.com)