In product development, it's a mistake to assume that other people want what we want.
I used to own a couple of retail shops; we sold snowboards, skateboards, and clothing. One day I was reading Adbusters magazine and heard about their new project: Blackspot Sneakers. These were shoes "made with hemp, recycled tires, vegan leather and produced in fair-trade factories". The idea was to create a grassroots brand, that produced a sustainable product. This was right up my alley: I loved the idea. Normally, making buying decisions for a retail store is something you do carefully: you're essentially risking your capital on the hope that someone will pay retail prices for what you've ordered. But in this case I was so passionate about their mission, that I instantly called them to place an order. I didn't even balk at the 25 pair minimum, or the high wholesale cost.
The shoes arrived. As my co-founder looked at me quizzically, I set-up a display with all the shoes, and a description of their social and environmental benefits. I featured them right at the front, as customers walked in, and promoted them in advertising. I started wearing a pair myself, and would hype them to whoever would listen.
No one wanted to buy my sneakers. It turns out, our customers didn't really care about shoes that embodied social justice and sustainability. Those might have been my values, but our customers had a completely different set of criteria: what expresses me as an individual? What will look good at school? What brand do I identify with? What skateboard pro do I look up to? Furthermore, they had a certain perception of value: to them, Blackspots just looked like expensive Chuck Taylors.
Nothing teaches you the value of finding out what customers really want better than trying to figure out what kind of clothes they're willing to buy.
When building software products, the risk is the same: just because I like something, doesn't mean my customers will. I need to sacrifice my own desires, and find out what my customers truly want. I can do this by observing them (and how they actually buy and use our products), and by listening. The key is to find their underlying motivation. To quote David McClure: "Customers don’t care about your solution. They care about their problems."
The funny thing is: I love my Blackspot sneakers. I've had them since I originally ordered them in 2005. My buddy Keenan was the only other person who bought a pair, and he loves them as well. We've both been wearing them continuously for the last 7 years, and they're only now starting to fall apart. I recently discovered a brand-new, un-opened box in my basement. It was like Christmas. In my case, these sneakers were exactly what I was looking for.