I run S3stat (
https://www.s3stat.com) and Twiddla (
http://www.twiddla.com) by myself and they combine to bring in a nice living.
I built both with the stated goal of bringing in recurring income while minimizing the amount of time I actually spent "working". As such, I had plenty of time along the way to bootstrap via consulting work and to travel and otherwise lead an interesting life while the product businesses ramped up in the background.
They're both ticking away nicely now, to the point where it's Officially Silly to continue working for anybody else, ever. As a result, "work" hours are defined as the ones where it's raining, the kids are in school and I've been mountain biking recently, or it's been sunny for a week and I need a rest day. Even with those constraints, you'd be surprised how many new features get shipped.
I mention this side of the business by way of convincing anybody sitting on the fence that it's probably worth giving this whole SaaS thing a try. It really doesn't impact your life in the way a "startup" would, can be done while still doing gainful work for others, and doesn't take much in the way of capital investment.
But if and when it starts paying dividends, it does in fact get as good as it seems it should.
Good luck!