Pfui - 3:43 am on Oct 28, 2010 (gmt 0)
Another issue has to do with copyrights. And, of course, NOINDEX tags, in addition to regular access/indexing controls. (sighs) My jury's still out on the benefits.
The screenshot on the site you cite -- [webfreelancer.net.au...] -- shows the preview is a heckuva lot larger than the average thumbnail. See the original example larger here: [blogstorm.co.uk...]