I find that the removal of the tag from the sheet of 48 that they come on difficult. Once placed on the club my GC3 gets club data well over 95 percent of my strikes. Difficulty comes in with lob wedges, bladed strikes and topping of the ball. I'm guessing that monitor camera just can't "see" the tag.
When I bought mine, years ago, they did not come with instructions. My mechanics are to use a scalpel to get on the sticky side of the tag then place my finger on top of the scalpel and then place it on the club and push down on the tag while removing the scalpel. I screw up about 1 in 4 tags.
All said, I still give the tags themselves 5 stars because they are the only way I know of to get club data.