The short answer is yes, they work. Frontline does not repel ticks and fleas but is supposed to kill them as they walk through the fur and/or bite. When we adopted Zoey she was full of fleas and the Vet noticed that because Zoey was treated at the shelter the fleas were not acting normal. The Vet gave us a couple of months worth of Revolution so Zoey could get the benefit of that medication. The long answer is that they may work but it depends on your area as was noted above. Will the generic version work ... can't say. As far as messy, Frontline and Frontline Plus leaves a "spot" on the dog where you treat them for about 48 hours but it's not greasy.Do any of the flea/tic products really do what they claim, for as long as they claim? I live in northern NJ, and my dogs don't get into areas where there are tics. I'm not really sure about fleas. We don't take them to dog parks where contact with other dogs is frequent, although when walking the one dog, he does have occasional contact with other dogs.
I have been using "PetAction Plus", which is a generic FrontLine Plus product. I don't like administering it, as it is kind of messy. I have my doubts as to how effective these products are, and whether they are really safe for our dogs, and ourselves.