Earlier quoted context omitted.
Rather than just use an email solution Google built GMail into a massive email solution despite it not being a core product Sometimes that's just an opportunity
> ... not being a core product Technically true, because Google's core product is ads. Also fundamentally wrong, because Gmail serves as a massive source of ad targeting information, in addition to being a high-engagement canvas to display those ads.
It was an unproven long shot when they built it.