BACF is allowed some commercial freedom to operate differently from BA and BAEF and take into account the competitive situation at LCY, in terms of what other airlines do. The other factor is that almost all BACF flights are 2 person cabin crew, one initially work CE, the other ET, before CE joins ET to complete the service (depending on flight length and passenger numbers). To have buy on board realistically would need 3 cabin crew or CE to be removed, neither of which is financially sensible. Given that BACF has some long routes (Greece) it has to do some catering. When Tourvest started buy on board at LHR and LGW there was talk of LCY following, but it simply never happened. Currently BACF don't operate wifi aircraft so the current LHR and LGW ET catering model won't easily work anyway.