I wonder about the extent to which the GrubHub/Seamless model will prevail and the extent to which the ChowNow model will. My brother works for the latter, and now that I know what to look for I've seen a fair number of NYC restaurants using "their own" ordering systems.
I think the market will be able to support both models for quite some time, as Seamless/Grubhub will never leave high population density markets until delivery problem is solved.
What's the difference? At a glance, it looks like Seamhub organizes everything under their brand, whereas ChowNow makes a custom app for every restaurant.
The latter seems nice if I already have a restaurant in mind, but if I'm too lazy to cook on monday night, I'm not going to go through the apps one-by-one.
I'm fairly certain that Grubhub also allows (and powers) restaurant ordering on the "restaurant's website" -- essentially it brings you back to a Grubhub page but it can be directly linked from the restaurant's site.