I don't think that Buddhism is a pop fad.
I agree. I've heard this a lot over time, but is there any actual evidence it's ever been a fad?
I don't know. Lot's of people joining since the 60's, but only a small few actually studying and practicing for decades seems to be the case with Buddhism in the West. People naming themselves Buddhist when actually they knew very little about it. Yet they flocked around lamas, roshis, monks, you name it, but their interest was not that profound or so people say. They could end up in Buddhism, Hinduism, Hare Krishna, etc. Many couldn't tell the difference. Can we call this a fad? I haven't lived through the process neither did any research, but I've heard stories. I guess someone older who has lived through this can say something more accurate. I was born in 75. We may have Buddhists in this board who converted earlier than that.
I'm not sure if evidence was rigorously collected, but my intuition (so its worth is limited) tells me that the fad has passed (about 10, 15 years ago) and nowadays less and less people are becoming interested in Buddhism, but those interested tend to apply themselves harder than the average Buddhist from the 60's-90's period (note the word average, please). I suspect it has something to do with the "Generation Me" ideals, as J. Twenge coined it, and the abandonment of the spiritual quests which was more usual in the baby boomers. People became more and more consumerists and Buddhism (or spirituality in general) was replaced by Spas.
These days being a Buddhist is no longer fashionable. It's becoming something rare. If we look at many sanghas (this is not difficult... just go through a lot of sites and see the photo albums) we can notice that most are comprised of middle age/ senior people and only a few members have less than 30. I think in the old days it was the opposite. A lot of young people and a few seniors.
Someone correct me if I'm wrong. This is just my perception of how things are, but I don't have solid data to confirm this. Just my impression from what I see and hear here and there.