I had an older gentleman come up to one day when I was merchandising and said he wanted some sunscreen "that had that SPF in it". I explained that "SPF" wasn't actually a substance but stood for Suntan Protection Factor.
He got quite upset with me and insisted that he had heard about a product "that had that new SPF in it". I tried again, showing him several bottles and explaining that the higher the SPF factor, the more sunscreen (like PABA or oxybenzone or titanium dioxide or another substance) it had in it.
He wasn't buying it! He KNEW what he wanted and he was GOING to get it. I was told I had no idea what I was talking about.
So I handed him a bottle of our product that was 60 SPF and told him he was right, the bottle was full of SPF. He left satisfied.
Sometimes you gotta do what you gotta do.......
Frankly, you don't need anything over 30 SPF *IF* you use it correctly and frequently. But, if one brand puts out a 50, the other brands have to put out a 60, then a 70, then a ...... It's just business.
A very pale young English guy told me one day that he was here for three days and he wanted something that would give him a deep brown tan. I suggested a tin of brown shoe polish. After we had a good laugh, I explained to him that he had two choices.....a faint "glow" of tan or a bad sunburn....but he wasn't going to get anything else in three days, not with that "English Rose" complexion.