One of the most annoying issues facing blog search engines today is blog spam. Unfortunately, it's relatively easy to create a new blog - or even thousands of blogs - then create what is absolute crap content in the form of scraped content from other sites. While there is nothing preventing people from starting sites like this, they are of no value to blog search engines trying to provide high quality results to their users.

So, how should bloggers deal with the splog issue? Technorati has chosen to use the link popularity of blogs to determine the authority of blogs and allows users to filter based on authority levels. Does this work? Yes, but it's certainly not the only metric that could be used to filter spam.

Ask.com launched a new blog search site today that takes an entirely new approach to determining authority: Bloglines circulation. Bloglines and Ask are sister companies under the IAC umbrella, and are developing some interesting synergies with the new enhancements coming out in both products.

By filtering results for blogs that have Bloglines subscribers, users can easily drop splogs from their search results since horrendously poor content, including splogs, would gain no subscribers at all. By the way, if you haven't noticed Bloglines circulation numbers before, they're published at the top of each feed that you view. As of this writing Technology Evangelist has 82 subscribers to this blog through Bloglines. Click here to be number 83.

Ask.com's other new features include RSS feeds for blog search results, and direct subscriptions to blog feeds appearing in search results. Rather than just providing an RSS link, Ask makes it easy for users by providing subscription links to popular RSS readers, including My.Yahoo, Newsgator, and Bloglines (of course). Popular bookmarking options, including Digg and Del.icio.us are also available for easy bookmarking directly from search results.

Also worth noting is Ask.com's unique ExpertRank feature where sites are sorted first grouped by topic then ranked by authority. This is designed to provide results that are authoritative on a given subject rather than results from high authority sites that happen to mention a given subject. For example, a site like Micropersuasion should rank high for PR related search results, but if Steve Rubel happened to write a post about something off topic like hockey, the result shouldn't rank particularly high for hockey related terms.

So, what does this all mean? First, if your blog doesn't have at least two subscribers through Bloglines, make sure you bump that up so you'll make it over the first authority filter. Second, if you find ask.com's blog search valuable, but would like more features, try searching from within Bloglines. The Bloglines version of the blog search product is ask.com blog search on steroids. Third, expect new features from Google Blogsearch, Icerocket, and Feedster in reaction to Ask.com's latest moves.