The following websites have dropdown carts:
www.matchesfashion.com/mens
www.asos.com
In my opinion they work well. Once filled by the user hovering the basket link and the cart appears until the hover away. I am thinking of making the same but rather than hover, they click their basket and it appears - the basket box does not move until they click close button.
Why? It makes the user interact - they have to move their mouse, press the close each time; It is my opinion that this makes them feel as if they are in control of the shopping experience and it creates better conversions and more sales. Is this a correct assumption? Should such carts be given a close button or is the hover-to-close option more usable?
See my before and after examples.