Cleaning carpet yourself can actually be quite an expensive undertaking once you consider everything that goes into it. You have to rent a small carpet extractor, haul it home, buy some soap or chemicals to clean with, read a bunch of instructions, spot treat problem areas, pre-treat traffic areas, and run the machine and try to figure out if everything is working or make sure you don’t put too much soap down. Now you have the issues of over-wetting the carpet, a bunch of chemical residues, your carpet is wet for a long time, and your water wasn’t even hot enough to kill dust mites that are living in the carpet. Not to mention all the time, energy, and back breaking work you put into it. Then all the spots begin reappearing a week later because there is too much soap residue left in your carpet. Now your only option is to do it all over again or hire someone with some knowledge on how to do it right.