Originally Posted by
ethernal
These companies sometimes purchase bulk unpublished fares that are cheaper than published fares on delta.com. But other than that edge case, in general, no there is no benefit.
I once bought an AF ticketed, DL marketed, VS operated TATL and DL operated domestic, itinerary on Expedia and it was insanely cheap compared to anything offered elsewhere.
But unless something similar comes up, I wouldn't touch an OTA.