Are flea sprays good enough?

i was wondering if using flea sprays like adams plus flea/ tick mist from petsmart, is good enough to eliminate/ repel fleas on my 2 cats and 2 ferrets, along with the house if i use it right. buying revolution for 3 months worth of 4 animals can get expensive.. so i was wondering if this is well enough. even if i only use it on the cats and the ferrets get revolution for 3 months OR i use one month for each animal and continue with the spray.. alls im really asking is if a spray is powerful enough. thankss<3