For years and years we purchased our flea and tick control from the vet,who sells three very pricey brands. Our vet is a half hour from us,and we ran out, so I picked some of this up at a local store,and I was shocked at the price compared to what I was purchasing from the veterinarian. I compared the active ingredients, and there were the same. I have used this since that day a few years ago. I have had absolutely no problems with either of our dogs. We live very rural,and our dogs are not exposed to other dogs, so fleas are not a problem,however, we live in a very heavily tick infested area,and it is not uncommon for us to get several deer ticks a week on us. With PetArmor, the only ticks that I have pulled off them have been dead ones. Application and the frequency of application is the same as the ones the veterinarian sells. I believe it lasts longer than thirty days, because we have been late in reapplying and have still had good tick control. All I can say is; why pay more for a product that has the exact same active ingredients? Why pay for another company's advertising? We have two dogs, and flea and tick control is costly, so I am glad that I found an alternative to what the veterinarian sells,and that it is just a fraction of the cost.