I don't use frontline on my dog very often but I do need to purchase it occasionally to have on hand if we need it. Usually, I order it from Amazon because the prices are much better than the pet stores near where I live. There was one seller that had it listed at a really low price the last time I ordered it and I was thrilled. Did you know that just because it's in the frontline box doesn't mean it's the real EPA approved for sale in the US frontline? The seller seemed genuine enough. The box in their picture was the box sold in the US. The box I received was a box of the US sold frontline. BUT the product inside the box didn't match the numbers on the box and looked different than what I had purchased in the past. When I called the company line and described it, they confirmed that it was a scam product and recommended that it could be dangerous to my dog. The seller was predictably difficult to contact and unpleasant about the returns process, wanting me to pay un-reimbursed shipping to return it to them. Luckily, Amazon is very reasonable when this type of thing is brought to their attention. The next order of frontline from a different seller was fine and the correct product. That price was lower than the pet store but not anywhere near as low as the scam product. Buyer beware, I guess. Sometimes the deal really is too good to be true.