OK, so i know this is a pretty standard offer (exactly what i thought when i looked at it), but after a second glance i noticed that it was on ALL ales, rather than just a select few, even the ones that usually cost £2.15 (which are often excluded from these offers). It is the selection i believe to be hot, not the price (though the price is good, just not uncommon).
this was in the sainsbury's central on tottenham court road, presumably in other branches also
expires 12th feb i think
hope this helps someone
(haven't checked online, could be there?)