I was just reading an article in a national magazine that warns that counterfeit products for such items as Advantage and Frontline are showing up in various stores. It warns that you should buy such products through your vet. If you do buy at a store make sure that it has the insert since most counterfeit ones don't have them or have them in only a foreign language. Also check the applicator for the manufacturer's name and the EPA registration number. There is a web site that will help you identify counerfeit products.
www.epa.gov/pesticides/factsheets/petproduct.htm
What will they think of next.