Google Data Highlighter Success

Has anyone used Google Data Highlighter on product pages, and had success?

I'm also wondering if any automated tools have been created to do this on a vast amount of pages.

I've had some hits and some misses with the GDH on a couple of my clients' sites. Somewhere halfway through my optimization google seemed to have changed something in their algorithm, making me start from scratch, but it looks steady now. If you're at least a bit technical, I'd recommend using the Structured Data Markup Helper.

Wonder if an automated program would work doing the highlighting.