The problem with treating fleas is their lifecycle. You have to understand what you're treating.
Adult fleas make up 5% of the population, so only a tiny percent are adults, the rest are pupa, larva and eggs. Nothing really kills the pupa, so at best you can kill the other life stages, but you still won't get rid of the population. Frequent and very very thorough vacuuming can encourage the pupa to hatch and then you can kill them, and it will also suck up a lot of the various stages. It can take up to a YEAR for pupa to hatch, so you have to keep treating pets for a year after fleas are found on them or in the house.
Borax can be used in the carpet, it dries out the inside of the fibers and makes it a poor environment for fleas, so sprinkle in borax, and then vacuum.
The spot treatments on the pets are the best bet, it can really keep fleas down, and don't use the cheaper versions. I've seen some really bad reactions to products like Biospot. Products like Revolution (which also protect against heartworm), frontline, advantix, are the best. ALWAYS follow package guidelines, some of these products sold for dogs are TOXIC to cats.
To get rid of fleas you need to clean everything, vacuum frequently (daily for a few weeks), use borax in the house and yard, and treat every pet.