Advantage works by killing adult fleas, while Frontline kills fleas at multiple life stages and also kills ticks that can carry Lyme disease.
The Pets' Guide from WebMD suggests using Advantage, Frontline or Program to safely and effectively control fleas on cats.
It is also my understanding that Frontline kills the fleas that bite your dog, but it doesn't actually repel them.
Ticks also enjoy human hosts, so it's important to have your dog on a tick control program such as Frontline.
Frontline Flea & Tick Control has the ability to kill 100 percent of fleas within 12 hours of applying.
Some of the stronger Frontline products may actually repel fleas, so that's another question for your vet.
Spot-On flea control products such as Frontline, and Advantage are useful in the fight to control fleas.
For example, Advantage or Frontline will kill 98 to 100 percent of adult fleas within 24 hours.
According to 1-800PetMeds.com, Frontline can cause irritation at the application site.
I have a two and a half year old spayed Chow mix, and she is on Frontline.