What’s the measurable value of blog syndication?

1. Syndication builds blog traffic: as I note in this post, in addition to the link/SEO value, syndication drives about 6% of all traffic to my blog: http://webbiquity.com/business-blogging/how-to-get-more-blog-traffic-real-world-data/
2. It improves search ranking: links are crucial to generating search rankings and traffic. While it's impossible to precisely quantify this, in general, links from higher-traffic and high authority sites (e.g. b2bmarketingzone.com, socialmediainformer.com, Technorati) have more SEO value than links from general directories and syndication sites (see http://webbiquity.com/business-blogging/100-blog-directories-and-rss-sites-for-promoting-your-blog/) (though even those links have some value).
3. It increases your influence. Syndication "gets your name out" and positions you as a thought-leader in your industry. What does that do for you? It generates more Twitter followers, blog readers, searches for your specific name or brand, and additional links to your content (which, again, helps with SEO). In terms of generating business results from that increased traffic, see http://webbiquity.com/business-blogging/20-ways-to-generate-roi-from-a-corporate-blog/