This is a big shift in in-flight Wi-Fi: Delta is taking a big move in expanding its already extensive Wi-Fi coverage. Delta committed to full mainline fleet coverage—these are the larger planes that carry more passengers and typically fly longer routes—but regional jets seemed less likely. Shorter routes with smaller numbers of passengers would make it seem quite difficult to get a return on the investment.
Nonetheless, Delta has plans to put Gogo Inflight Internet on 223 of the Delta Connection subsidiary and partner aircraft. The planes have between about 65 and 76 seats, according to Delta's press release. More critically, all the planes have first-class sections, and the commitment appears to be put Wi-Fi service on all routes with first-class service.
It's possible that the investment is relatively low compared to the customer loyalty it may engender. Those who want continuous Internet access across a route, and who are more likely to buy or upgrade into first class may be so valuable that the amount realized in additional seats purchased and higher fares (as regional service is often not as competitive as national routes) is where the revenue comes from to balance the accounts.
Delta currently has over 700 mainline aircraft in operation, and 549 of those have Internet service installed. The regional jets will receive Internet service during 2011.