Amazon is full of third-party sellers that list their items with the massive online retailer for better exposure, but, as the Consumerist notes, that makes for a lot of competition. Competition drives down prices, so much in fact that Amazon prices can fluctuate a ton over the course of a single day.


The Wall Street Journal teamed up with Decide.com to analyze price fluctuations on Amazon. The changes from third-party sellers on Amazon were far more frequent than other sites:

Last month, retailers on Amazon.com changed prices on a Samsung 43-inch plasma television four times over the course of a day, between $398 and $424, according to Decide.com. Around midday, Best Buy boosted the price to $500 from $400 before dropping it back down, while electronics retailer Newegg in the morning raised its price to $600 from $500.


If you've ever sold something on Amazon before, you've probably noticed this. You set the lowest price, and later in the day you notice that someone has attempted to undercut you. This sucks if you're a seller, but it's good news if you're a buyer: it means that prices will change super often, even over the course of a day, and you can get the lowest price by checking back frequently. Generally, we recommend monitoring prices over time, but on Amazon, it might be worth keeping that tab open all day long and jumping on a deal as soon as you see it.

Coming Soon: Toilet Paper Priced Like Airline Tickets | Wall Street Journal

Note: A previous version of this post recommended posting the same item for sale in order to cut other's prices, a suggestion that many (understandably) took issue with. We agree, and have updated this post accordingly.