For some reason, and it may be cost, as far back as I can remember, airlines operating smaller aircraft have always been reluctant to advertise, preferring some other promotional technique such as personal appraoches to travel agents.
Flybe have plastered the buses in the Bristol area with details of their flights out of BRS.
They also conducted a high profile local television and local newspaper advertising campaign in this area.
In fact it seems every Bristol bus is either advertising Flybe or easyJet - a bit of an exaggeration but these airlines are certainly using this medium heavily.