I have a not-so-small Groupon addiction I'm working through. The daily deals flood my inbox each morning and I'm helpless to turn away. Full massage session for half price? 15 yoga classes for the price of 10? Brazillian wax for one-third the normal price? (Hang on to your hats for THAT blog post.) I can't say no.

Which is how I ended up paying $45 for one month of 12 Crossfit sessions.

In case you're not familiar with it,...