Pros: Don't know
Cons: Lousy customer service. Doesn't work as stated.
We used Frontline on our three indoor cats for three months and the fleas still persist. The interior of our house was properly cleaned and treated, so we do not think that the environmental conditions overwhelmed the efficacy of this product.
The Company's customer service is all but worthless-just like their product.
My wife tried to get a refund for just the last month's application and was given so many hoops to jump through that it just isn't worth pursuing.
Rumors persist that the fleas are becoming resistant to this product.