chess.com and lichess
Despite lichess being better in every way except marketing, it's still #2.
It's very impressive word of mouth got it to #2, but marketing experts are marketing experts.
the name matters, chess.com= automatically associates with something central about chess. (dot com) lich-ess can be read as lich-chess or leeches, both leave repulsive associations, effectively sub-conscious anti-marketing.
The "lichess" name is terrible, the way the word itself looks is off-putting.
It's like why they use sharp points in the hazmat symbol, it just looks bad even if you don't know what it means.