[spike021]

FOMO means Fear of Missing Out.

So, say you're interested in a certain smaller brand that may not sell thousands or more copies of certain items, but something on the order of 50, or 100, etc.., then when you see that others have been purchasing said items you worry you'll miss out on your chance to buy one, and then you'll be one of the only people who like the brand who don't have said item.. thus, you wind up purchasing too.