Teesside??? And you say Stansted hasn't succeeded. Might want to take a look at Teesside's passenger stats. There's small and then there's small!
Stansted, being 30ish miles north east of London is not in the "wrong place." You can get to Embankment in less than 1 hour by road (it takes longer than that from Gatwick since most of the route is not motorway) and with rail improvements, Stansted would have better rail access as well. It doesn't matter how far an airport is from the place people want to go, as long as people can get to those places quickly and easily, and that is what the problem is at Stansted and needs adressing. I terms of the location, Stansted is no worse than Gatwick, Luton and Southend. Tbhey are all similar geographical distances from London and Stansted has a huge catchment area, all the way through East Anglia, London and the Midlands. Gatwick is in the "wrong place" for anybody who lives north of London!