Hmmm...guess the post muncher thought my post was too long (who me? write long posts?)
It kept taking the middle paragraphs out so it didn't make any sense.
I'll try breaking it up into multiple posts & see what happens.
Revolution is different from Advantage and Frontline in that it is a prescription-only product, so any legitimate online retailer would require a prescription from your vet if you wish to purchase Revolution online (just like buying human drugs from a legitimate online human pharmacy). Any online retailer who offers to sell you Revolution without a prescription is breaking the law, and is more than likely selling counterfeit product.
As Yosemite pointed out, Revolution
is different in that it is not only used to treat fleas, it is also used for prevention of heartworms and other parasites.
If you're considering buying Revolution online, the fact that you'd need to talk to your vet's office to get a prescription first would provide the opportunity to ask if he thinks purchasing Revolution online would be safe. If he approves of the idea, you could ask if he could steer you toward a site he considers reputable.
My vet's clinic staff didn't have any problem with sending our dog's heartworm prescription (Interceptor) out to the retailer I chose (they have a list of online retailers that the vet won't write prescriptions to because of quality or legal concerns).
They told me that they understand the need to watch expenses when you have multiple pets, and that the reputable online retailers order medicines from the manufacturer in such volume that their prices for the same medications are much lower than a single vet clinic can match.
I've never used Revolution on my pets, so I can't give any personal feedback about purchasing it online, but I'm sure your vet will be able to offer guidance if you check with him.