As Google makes it more and more apparent, their search engine looks at the words on your site or blog. Then they display your site in the search engine under those topics, or keywords, that THEY think you are about.
How right or wrong they get this varies, but keep in mind, Google get paid (in a large part) as to how right they get this.
They are making a decision on what you are talking about. There is a lot of merit to this approach.
If you are at a party and you overhear someone talking about skiing in great detail–their experiences, the equipment, the best places, good techniques–you might assume they actually know a lot about skiing. Does it matter if you find out if that guy is an engineer? Probably not, they really sound like they know a lot and go into a lot of detail. Would you trust this guy if you were on the slopes with him? Maybe-probably.
Now what if you find out same guy is a ski instructor. Now you would really pay attention to him, right? Maybe even Spend Some Money, say, pay for ski lessons, buy the equipment he recommends, make reservations at the same place he goes.
This, my friends, is blogging for business. It doesn’t have to be complicated. Literally, you can use the same topics and threads you would bring up at a party about the things you know about…your business. The thing is, if you are going to have a site, you can make it more than on online brochure by making a little conversation regularly. You never know who is listening in, but keep talking someone will listen in. And Google will help interested parties overhear your conversation.