OMG, this is absolutely one of the easiest and quickest ways to make money online.
First off, when you run a site based on your own hobby, you are obviously already
knowledgeable in that topic, so, information is already on hand.
Secondly, the old adage applies... If you do something you love, you'll never work
a day in your life. The saying holds firm in that when you create a site based on a
hobby, it doesn't ever feel like "work", just "fun".
Thirdly, when creating a site and business around your own hobby, you will be very
PASSIONATE about it and that WILL shine through in everything you do, be it a blog
post, an email promotion, a forum post, whatever...
I could go on and on, but I am sure you get the point.
As far as HOW to turn your hobby into a business, well, lets clarify that when I think
"business" I am not talking in the normal sense of what people think of as a business.
I am simply talking about "making money" with your hobby... and that can be done in
a number of ways...
Starting a Blog
Starting an Online Store
Creating A "Service Offering" Web Site
For example, I am a professionally trained chef as well as a programmer AND en EMT.
I LOVE helping people, LOVE IT LOVE IT LOVE IT. So, I started a website a few years
back which was geared around offering safety tips and medical related bits of info.
Not that I ever expected it, nor was it my plan, but I made a killing by using affiliate
links to promote products that I myself used in the industry. I also started a mini
membership site in which I offered general how-tos as well as advanced information
for anyone looking to get into the medical field or who were interested in just learning
more.
Now, the "chef" in me also required me to start a "food" blog a few years back as
well. I posted recipes, tips & tricks, and all sorts of other information (what wine
is best with what meat, substitutions in recipes, etc.) and again, I had started
a mini membership site in which I offered a plethora of my own recipes, tidbits
of not-so-well-known tips and tricks (stuff I learned in Culinary school that normally
only classically trained chefs would be privy to -- at that time anyways), and again,
I made a small killing.
Whenever I worked on any of those sites, it was NEVER like a "chore" or something
I "had to do", it was all stuff I WANTED to do and stuff I ENJOYED talking about, so,
the money I made was just icing on the cake sort to speak as whether or not I made
any money, I would have still created the sites and whatnot.
Now, one downfall, however, is that if your business takes off too quickly, or if problems
start to arise, it could easily turn you OFF of what was once your hobby. So, you need
to make certain that if the "FUN" ever starts to subdue, find a way to GET OUT, LOL.