L.B.
I've used them for special occassions with a dress that has no back. They work great. I like the actual cups much better than just the tape that covers you (and much more support). I've never had a problem with them falling off, even when sweating. The adhesive is pretty strong (in fact it kinda hurts when you take them off). Of course, I only wear a B-cup so I don't know how well they work for larger sizes.