Stemschicky, I never have... but that's because I am an extremely focused shopper. I don't dawdle in aisles and wander around from shop to shop in RL, and on eBay I tend not to check "great buys" since inevitably they don't pertain to the things I want!
I usually only look for specific items, and that means all the Great Buys buttons and Thought You'd Like This buttons do absolutely nothing for me...