Edwin - 3:27 pm on Mar 11, 2010 (gmt 0)
My "problem" is I quit my day job years ago, so I'm semi-retired to the point where I simply maintain my site(s) and don't have a real job, so I burn through most of my site's earnings to cover living expenses for my family. This makes it a higher risk investment to me since I have more to lose if things go south. But if I had a day job, it would simply be money in the bank each year, doubling and tripling.
One solution might be to expand your site network so that you've got plenty of money in the bank at the end of the year, even after living expenses. If they're the kind of sites that "run themselves" (the best kind!) then once built and promoted, they're like an ATM stuck on "dispense money" :)