Originally Posted by
Bksmithca
My take on reading the news release is that Virgin used the DL code share on a flight that Delta would not or could not operate. My understanding of the code share program is that the codes are used to reduce the number of half empty planes flying from A to B but still allowing SLF to collect points on the frequent flyer programs. To use the code share it would have to be a route that Delta and Virgin shared which wasn't the case here.
Codesharing has been around for decades. There isn't really any mystery about how it operates.