I suppose it depends where they live. For the wealthy west London area there is heathrow nearby. For City types there is LCY. But I'm not too familiar with the Southend area. If there are enough people willing to pay BM it may work as Southend is now pretty well established. There are no early trains however so the business folk would have to either taxi or drive there. So who knows what may happen. As already mentioned, most Londoners think BMI went the way of the dodo. It may be hard to tempt people to an airline that they may see as being back from the dead.