I'm thinking any mountainous region like Kashmir, or vast area like the Canadian North, where supply is reliant on weather and availability of planes. Imagine an airship line running into Kathmandu saving those bigger planes from having to land there, as it is the scariest airport EVER to have to fly into. I can only imagine the shot every pilot has waiting for them when they land.
Construction, the airship itself is a good platform for a mobile crane with less moving parts than a helicopter in the city.
Cruises has been mentioned, imagine touring the Pacific Rim, or the South Pole. These offer a long term cruise opportunity, there is a growing number of retirees that pretty much live on the cruise ships. Floating retirement homes? Ha maybe a bit much.
Offshore anything.
Way out of left field, a World Wide Wifi network, using high altitude drone airships.
Evil Villains are always a good avenue to try when you don't know who to sell to.