This can be ideal for people who don't normally have a flea problem, but don't want one to show up, either. For an active problem, or a pet with flea allergy, this may not be enough. These are applied to the skin of the dog and spread by themselves. Frontline also works on ticks. These are effective anywhere from one to three months and are now even fairly resistant to the swimming efforts of your canine companion.
Side effects seem to be minimal.
I did try them on my own pets, though. My barn cats have had a topical flea product for the warm months here in upstate New York for 3 years now. I've never seen a single flea in all that time. The year before, I removed 23 ticks from Beep and 3 from me. So I'm sold on the new flea control methods.