Put advertisement but make sure that your blog visitor doesn't get irritated when ads pop up one after another like a flood.
Write regularly, neither too often nor too rarely. Two to three blogs a week is a good frequency to maintain.
Don't just type, talk to your audience. Blogging is way big a market on internet and people will like you if you do more than just providing information. Suggest, express, appreciate, criticize and have an opinion to build a relativity to a like minded audience. Make them feel that their visit to your blog matters to you.