There's a lot of competition, but talent floats to the top. Most blogs have one reader if you count the person writing it ... so if you can write a good one, it's actually not that much competition at all. Stox posted that 74 % of the sites hosted on *.blogger.com are spam, so if you regularly come up with insightful content, that alone will put you ahead of the pack.
Example: another member of this forum has a blog called
The Great Library. See how the guy just got a free link from somebody else, because it's relevant to the topic at hand? That's organic growth. The guy is a great writer and picks fascinating topics, has a way of making abstract, scholarly material seem everyday and plain. You don't need to write about the same topics, but you need to write well enough to get other peoples' attention, and respect.
You can submit your blog to every directory in the world in the hopes that it will raise your PR, exchange links, game social media sites, post on forums and blogs, write articles, and basically work on promoting your blog about 20 hours a day. Or, you can focus on unique and compelling content, and the marketing work will mostly be done for you. When you write a good post, other people will link to it when the topic comes up.
You still need to "get the word out" at first, but that shouldn't take long, and once you take care of that, you don't need to constantly work at it.