Whenever I left the hotel, there was a pretty good chance that I’d get hassled by postcard selling 20-something Vietnamese men. These postcard sellers didn’t seem to notice that they were surrounded by other postcard sellers. They didn’t seem notice that I’d been hassled by 14 other postcard salesman in the last five minutes. They just blindly pushed postcards on me in public spaces. I imagine the first young entrepreneurial businessman who set up shop selling postcards at an attraction made a fortune selling postcards to American tourists. The 5th, probably made half a fortune. But now? My experience was that no one was making much of anything, and I had to dodge an endless line of postcard hawkers. I can only imagine that the guy selling postcards to the kids who were selling postcards was the guy who was making the fortune now.
This happens in business all the time. Someone stumbles across a good idea, they make a lot of money doing it, and then a crowd of people try to do the same thing without regard to whether or not it works or not for them personally.
This is why I experiment to see if a thing works or not. If it doesn’t work, I untether.
If postcards aren’t working for you, try something else. It might just work.