Visibility, i agree but they are No3 behind FR & easyJet in Europe
All depends where you live really, in 2014 they carried 24m passengers and have a 13% markets share at LGW, but not much point marketing yourself outside catchment area, that of course now includes BHX.
Re where they fly, if you click on flights on the home page, you can select your departure point, it then shows all destinations from that point, you can refine between direct and connecting flights, on this last point you are booked through, so its not a DIY connection, there are currently no connecting flights from BHX, but there are a total of 46 destinations listed from EDI, 39 from MAN & 93 from LGW
I would be surprised if there isn't a winter program probably AGP/TFS/LPA would be my guess
