Adverts, adverts, adverts

I have just turned on the telly to watch the Chancellor's pre-budget statement (sad, I know, but there you go). The programme on BBC2 was preceded by three adverts for BBC programmes - successively, Strictly Come Dancing, A Bach Christmas and Russian Godfathers. Do these ads achieve anything other than irritating the viewer? I know that it's the wasteland of daytime tv, but the BBC might behave more like a public service broadcaster and less like a grubby commercial operator.