I was looking forward to using these outside on my vinyl window sills, but could not get them to stick. I followed the directions exactly. Clean dry surface...applied correct side to vinyl and held firmly for 30 seconds. Also it was 42 degrees. All but 2 of the 10 I tried actually held. I'm waiting an hour to hang anything on them, but at this point I'm not getting my hopes up. Also is there a weight limit? I know they are made for lights, but like the other command products they are very versatile. Very surprised given the other rave reviews. Really hoping this was just a bad batch.