Amazon sold items with promotions, yes, activate the "Has Coupon" filter. The site doesn't show 3rd party sellers, so you won't be able to get what you want currently. It would be cool to see Amazon Fulfilled 3rd party seller items listed on here if that's possible though??
It is a option already, under the Filters in the Price Category there is a "Sold By" box that lets you choose between Amazon, Warehouse Deals and All Merchants. Fair warning though, it's a hot mess when searching through 3rd party as it picks up any listing that has a prime-eligible item in it no matter if it's the lowest price or not so you will get alot of junk.
Thanks tielknight, I stand corrected :-)
Thank you johnlawrence and tielknight for pitching in with responses while I was away from computer. You are both right. In general, many of the promotions that show up on item detail pages are not easily picked up by the search page filters, which is what so.cool is all about. There are some exceptions (like the Cyber Week sale that never seemed to end) that I can pick up with my filters, but those only capture a subset of everything that is going on there in terms of promotions. Thank you all for participating in the discussion!