Seems everyone has a blog these days. Technorati tracks over 70 million weblogs, with new blogs being added every day. If you just want to write an online confessional, your own personal little Jerry Springer show (as so many people do), you don’t need to read what follows. But if you want to create a blog that has the possibility of making some money, read on.

1. Make a list of what you love.

This may sound hopelessly Pollyanna for someone who wants to make money blogging, but keep in mind that creating a successful blog (however you define success) is going to take some work. You could create a blog about asebestos or mesothelioma or Chicago personal injury lawyers or whole life insurance quotes, or whatever is supposed to be the top paying keyword for Google AdSense, but if you’re going to bore yourself slogging through the work of maintaining a blog like that, you might as well get a real job. Don’t believe the hype. Few bloggers make money and most of those that do work hard and care about what they’re doing. See 25 Steps to Launching Your Blog and Making $100+ A Month in 30 Days for an idea of just how much work is involved.

2. Decide if you’re a diver or a scanner.

I owe this idea to Barbara Sher’s book, I Could Do Anything If I Only Knew What It Was: How to Discover What You Really Want and How to Get It. Scanners are interested in everything, while divers are intensely interested in one thing. You can have a successful blog that covers lots of topics (kottke.org comes to mind), but most successful blogs focus on a niche. Both kinds of blogs can succeed, but niche blogs seem to have better odds of success, at least in my experience. Futurosity is my “scanner” site and Upstart Blogger is my “diver” blog. Upstart Blogger makes several times as much money as Futurosity. The reason? My advertising is more targeted on Upstart Blogger. If you do create a blog that attracts a diverse audience, you’ll want to organize it in clearly defined sections that help focus your advertising.

3. Decide if you’re a tortoise or a hare.

I owe this idea to Aesop. Tortoises are slow and steady and their best topics are those that change slowly and have some longevity. Hares are fast and trendy and their best topics are hot and timely. Most bloggers are tortoises. Sure, the content may continue to change and evolve, but if you’re writing about blogging or macramé or gardening, your topic stays pretty much the same. You can also have a successful blog writing about politics or celebrities like Paris Hilton or Tom Cruise and Katie Holmes. But write fast; these sites need to be updated almost daily and your topic may only have 15 minutes of fame. If you can keep up the pace, though, you can be a successful serial blogger by capitalizing on the public’s fleeting fascination with the current hot topic.

4. Research revenue sources.

Okay, now you can begin to let greed into the equation. You want to make money, so do some research. And here’s a tip: you won’t make enough money from Google AdSense to quit your day gig and go sprawl on a beach somewhere. If you want to make real money, you’ll need to find the right affiliate programs for your blog or have your own products to sell. Start your search at Commission Junction and LinkShare.com. Make a list of potential advertisers that might fit your interests. Note how much they pay.

Upstart Blogger is a good example. I write about blogging. Most bloggers choose to host their own blogs. They need hosting. I advertise hosting. It pays my mortgage.

Look at the list of topics you care about. Look at your list of potential affiliate programs. Find the balance between passion and profits.

5. Case the competition.

I don’t believe in competition. There may be a million blogs devoted to your topic already (and there probably are), but the sad fact is that most of them are vanity projects that garner little traffic and earn even less money. Some people will advise you to stay away from popular topics. Actually, you want competition. You want a topic that is popular because that means: 1) there’s an audience for it, and 2) you have plenty of marketing opportunities. You study the competition to see: 1) what the successful blogs in your category are doing right (what kinds of posts get dugg, etc.), and 2) what they’re doing wrong (so you can do it better).

6. Consider your marketing plan.

When it comes to marketing your blog, there are lots of tips and tricks, but no magic bullet. You can optimize your site for search engines and dabble with advertising (if you’ve got the money), but nothing beats these three keys:

1. Post high quality content (at least somewhat) regularly.
2. Leave links to your site wherever you can by commenting on related blogs, etc. (see Case the competition above).
3. Have a link bait strategy.

I use how to’s (like this one) and templates for Pligg and WordPress as my major strategies for generating traffic. Make sure your topic lends itself to these three keys: you’re confident about your content, you’ve identified some competitive sandboxes to play in, and you’ve got some link baiting ideas.

Now that you have a topic for your blog, go read 25 Steps to Launching Your Blog and Making $100+ A Month in 30 Days.