Is this a hit board game? The number of BGG ratings and rank (13648) don't reflect that. Does it stand out in some way from the multitude of similar games?

Maybe it's a good game, but definetely not a hit.

Reading the article, it looks like it's a hit because Waterstones, a major UK book store chain, ordered and sold 15k+ copies. That means most of the buyers are readers, not necessarily the usual board gamers crowd. Hence its lack of ratings or attention on BGG.

Maybe it was a hit from the creator's perspective, but never heard of it and its like 13k down on the BGG list. Loose definition of "hit"