At a function for one of my clients I asked an economist what the most annoying part of her job is. She thought about it for a bit but couldn't think of anything: "I love my job!"
At the end of the night just as she was leaving she tapped me on the arm "actually the most annoying thing in my work is when I have to turn a selection of Excel cells into an HTML table to publish it on our website."
Bingo! Exactly 15 days later I started coding an Excel Add-in to solve this problem for her.