Right.
I can't speak for anyone else but this is what I know.
I've very rarely NOT had a cat and have fostered an awful lot, owned (if you ever do own them) at least 5 myself since being a grown up! And grew up with one as well.
Frontline doesn't work. Many people are finding out the hard way! It's useless and shouldn't be sold any more.
Our cat has always had one or two fleas, that's normal, but you rarely see them or notice them as they live on her.
What you do is you treat your cat regularly using something like advocate or stronghold. We have only once had any sort of actual infestation (I mean visible flea eggs where the cat slept, the cat licking herself tp pieces, looking unhappy, unable to rest) and that was last summer, when we were using frontline and fipronil.
I was almost in despair, but took her to the vet and got Advocate and it works brilliantly. The entire issue was over in days. I was told to treat the house but I didn't, and after about 3 days she was no longer leaving a single flea egg where she slept, she was actually sleeping soundly, she wasn't damp and spiky from licking herself and it was such an excellent relief to know somehting worked!
I used advantage every month - it was about £40 for 6 months plus one free month, so not that dear, and you can buy a script from the vet and buy it for less online. Having multiple cats would be a problem financially though.
The only thing I would say is think about vets bills. Our cat has rarely had a problem but when she has, insurance has not always been helpful, if she had had it once before for example. So I scrapped paying for it and we chance it now.
Fleas don't worry me at all.