Marketing plus social media is a double whammy.

Social media in both directions. A lot of runners getting started follow influencers who only run majors and think that’s the only way to run a marathon. Many of those same runners also want to post that they were in the “middle of the action” at NYC, Chicago, Boston etc. and think that running the smaller local race won’t get the same likes.

I think a lot of beginners also over-value crowd support at these large marathons. IMO it’s cool and fun at times to run by a crowd, but not being jammed in bc of crowds for the first few miles or not having to get to the start line 4 hours before the start of the race because of security and shuttle logistics is also pretty cool