I also see it that way. Remember how ChipMixer was simply the number one mixer everyone used? They spent quite some money here, but I would say it paid off (for the time they were up running). If I needed a mixer, the first thing in my mind would be "ChipMixer", and their signature campaign was the main reason.
It's good to hear that a bitcoin related campaign actually led to the usage of the product by bitcoiners.
I end up wondering why most exchanges don't want to run promotions on forums. I know they already have a large client base without promotion on this forum, but their involvement in the community can help this industry grow better. bitcointalk is the biggest discussion forum they deserve, at least they need to consider running a campaign as a bonus for contributors on this forum.
Could be true, but if they spend (?) money on research and see that their ads in other websites give them significant revenue increase, perhaps they find bitcointalk space less effective.
Another thing that crosses my mind is that perhaps the interest on bitcoin-related projects grows when something significant happens.
For example, mixers were advertised a lot when the non-sense about "clean" coins was in very high demand. Maybe because of the new regulations that governments apply.
Another example is the non-kyc exchanges which became more popular after FTX, or after the rumours/news about Binance doing money laundering.
Finally, it's almost certain that as bitcoin price increases, more people will join the forum. I don't care about the price change personally, but many people do.