It's the positive impact the concerts have on local businesses and the area. For example, the Armoury taking as much in 3 days, as they normally do in 3 months. The money it brings to local hotels, pubs, restaurants, etc...
Also the town was being mentioned pretty much every day for a month in the build up to the concerts on Radio stations like XS Radio. They even held a pre-gig concert in the market place.