[derivagral]

Didn't grubhub and ilk effectively insert themselves this way for food service to a lot of restaurants?

Somewhat relatedly, I know my local tech hub has a couple places that do leadgen like this for financial verticals and it has been... lucrative. In my local cases, usually either a license or a snapshot of supporting technology is part of the deal and the vertical is spun out as a new entity to the acquirer. Rinse and repeat several years later, when the "acquirer" has years-old versions of the original stuff and needs something fresh to reinvigorate their pipeline...