Track Your Logs
Study your logs to track buzz
You need to know who's talking about you. Check your logs and find out where the buzz is coming from. Who's linking to you? Who's bitching about you? Which blogs listed at Technorati, Blogdex, Feedster, Del.icio.us, and Daypop are hot on your trail?
Find out and then make your presence felt. Leave comments at those blogs. Thank people for posting links. Ask them if they want to be included on your special advance list so they'll be among the first to know about future releases, updates, etc. Collect positive praise and create a "buzz" page at your site. Testimonials are a great way to promote your app since third-party praise is more trustworthy to most people.
If the comments are negative, still pay attention. Show you're listening. Respond to critiques thoughtfully. Something like: "We appreciate the feedback but we did it this way because..." Or "You raise a good point and we're working on it." You'll soften up your critics and put a human face on your product. It's amazing how much a thoughtful comment on a blog can diffuse naysayers and even turn complainers into evangelists.