Yes, but designated areas; not everyone wants to stand, and family stands with seats should remain.
Someone (Sky Sports?) were asking fans outside Notts County this exact question!
encourages early sales and gives clubs better idea of numbers for policing
better than the usual match day price rise of a couple of quid; the early bird price is £5.50 cheaper than matchday!
Bizarre announcing it's sold out, but then not promoting these tickets which have appeared online, considering the fuss about it being a sell out.
I assume they are returns or something?