Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Always the best price on Amazon

I have four dogs and so frontline is a must. I always purchase from Amazon as the prices are almost half what my vet asks. Free shipping, packaging is always good. Items are always as described and new in the pack. IMO, no other flea treatment on the market works as well as Frontline Plus. Purchasing it in larger size is more cost effective. I eye how much I put on my dogs and use it on my cats too. Can treat 3-4 pets out of one dose.