If you were ever wondering how to get mass amounts of candle wax out of a carpet, the solution is to first scrape off the excess wax. Betty Crocker types would use a putty knife. Normal people can substitute with a butter knife.
Next, plug in your iron and lay down a sheet of paper towel, then a paper bag (if it becomes clear you are not going to melt your floor you can forgo the paper bag). Iron over the paper bag, removing the paper towel when it becomes saturated with wax. Repeat, 50,000 times.
You can speed this process along by using a hair dryer to help melt the wax if it's hardened. However, don't use the hair dryer on a really high setting or you will melt the carpet. And you WILL melt the carpet.
Of course, if you are like me you do not really wonder about this until the three-wick candle you were burning suddenly lets loose and dumps half a gallon of wax on the floor.
Thank goodness my carpet already looked like ass. I've got it mostly cleaned up, although it's a little stiff in places and also fused together in a couple spots from the melting. Considering that half a foot away there's paint all over the carpet from the shoddy-ass paint job they did, I don't think it's going to matter. Also, because I also used my steamer in this process for some of the final clean-up, that spot is WAY cleaner than the rest of the floor. I'll have to tromp on it or something.