Consider this — if a tree falls in a forest and no one is around to hear it, does it make a sound? OK, you've probably heard that question before so let's turn it on its philosophical head. If a product doesn't have a user, does it still serve a purpose?
Let the question sit for a second. Imagine spending tons of money and time to develop a web application that, for example, crunches metrics for Ruby code. The product has a specific purpose, so you assume a market exists, but haven't done any meaningful user research. After all, a lot of people use Ruby code, so there must be someone that can find your application useful. Then you release the product into the world and it's an epic fail. So what went wrong?
To answer that, let's look at software start-up Devver, because that's exactly what happened to them. After two years in operation, Devver crashed and burned in 2010, becoming another footnote in history. Co-founder Ben Brinckerhoff blamed the failure on the company's focus on the product, not their users. And without a user, their product served no real purpose.
As pointed out in this video from the folks at Extra Credits (as seen on Penny Arcade TV), the central element of any product is the user. Check out the video below, noticing how important the role of the user (or in this case, the video game player) is in completing a product's purpose:
You can craft pretty pixels and images, have steller interactions, but it doesn't amount to much if there isn't a user behind them. When it comes to the having a great product or a flop, a user can make all the difference. In other words, a product without a user is nothing.