When markets are new they are unproven, thus they often have limited investment targeting them.
That in turn means it can be easy to win in new markets just by virtue of existing.
It wouldn’t be hard to rank well creating a blog today about the evolution of the 3D printing industry, or a how to site focused on Arduino or Raspberry Pi devices.
Couple a bit of passion with significant effort & limited competition and winning is quite easy.
Likewise in a small niche geographic market one can easily win with a generic, because the location acts as a market filter which limits competition.
But as markets age and become more proven, capital rushes in, which pushes out most of the generic unbranded players.
Back in 2011 I wrote about how Google had effectively killed the concept of category killer domains through the combination of ad displacement, vertical search & the algorithmic ranking shift moving away from relevancy toward awareness. 2 months before I wrote that post Walgreen Co. acquired Drugstore.com for about $429 million. At the time Drugstore.com was one of the top 10 biggest ecommerce pure plays.