The 3M Post-it product was a product that was, basically, discovered by accident. The chemist was actually trying to make a stronger glue for tape but, instead, actually made a weaker one! It's NOT the same principle you describe with melamine. The chemist at 3M didn't INTENTIONALLY try to make a strong glue weaker (which is akin to INTENTIONALLY using an indoor product, outside.) Try and use a strong glue on the Post-it (which is akin to putting an indoor product outside), and see how many of these types of Post-its you sell. THAT'S the same as INTENTIONALLY putting an indoor product, outside. I'd like to see the line of home buyers wanting to buy a sponge!
During the early 1970s Spence Silver, a chemist in the 3M Company's Central Research Department, was trying to develop a new, stronger adhesive for tape, but instead managed to create a weak one. He mentioned the results of the failed experiment to other 3M researchers, including Arthur Frye, who recounts Post-it Note's history in an article on the 3M Company's Web site.
Frye says he remembered the new, weak adhesive as he was musing about the problem of keeping bookmarks in place in his church hymnal. "This was followed by a dull sermon, and my mind was wandering back to the music problem when I had one of those 'flashes of insight.' Eureka! I think I could make a bookmark, using Dr. Silver's adhesive, that would stick and remove without damaging the book," Frye writes.
Frye helped develop the prototype, and when the new bookmarks were ready, he attached one to a research report, then wrote a note on the blank bookmark. His manager later wrote his answer on the bottom of the bookmark and attached it to an item he was returning to Frye. "It was during a coffee break that afternoon when we both realized that what we had was not just a bookmark, but a new way to communicate or organize information."
The Post-it Note was born, and Silver's failed adhesive became the key ingredient of what today is 3M's best-selling product.