I have found that being personally interested in the product has a lot of benefits. First, if you're a user/consumer, it's easier to determine which features are most important as well as usability issues. It's surprising how unusable some products are because the developers never actually use them.<p>Second, and most important, a personal connection helps to get you through the dark days at the start. It's very emotionally draining to work on something that has no traction, no supporters, and just a bunch of naysayers. If you love the product, though, it can offset this emotional drain quite a bit.<p>In my case, I built a tabletop gaming (ie. DnD) CMS. In the beginning, nobody used it except me, and it was tough to go upstairs and hack away every night and weekend. However, <i>I</i> used it and that was enough to keep me moving. Now, we've got thousands of users and paying customers, and the motivation is much easier to find. But, I never would have made it this far if I didn't care so much about the domain.<p>Unfortunately for me, I think there's probably a lot more money to be made in "boring" areas. If you can keep motivated to work on a CRM or medical billing system, you'll probably end up making way more than my DnD website. But, it will definitely be harder to keep the momentum in the beginning.