Sgt_Kickaxe - 1:36 am on Apr 2, 2012 (gmt 0)
Custom descriptions should influence a click more than the stock snippet but I'm not sold on it being as big a factor as it might seem to be because
- Google doesn't always show the custom description
- Visitors don't always read more than the title in search
- A custom description may not be more influencing than the first couple lines of your text
Also, I removed descriptions on an entire site because the navigation text was being used as description in search results. Result: no change in traffic.