Spoke to one of my corporate hospitality contacts this morning and he's getting worried that his clients are cottoning on to Twickenham not selling out.
Also feel sorry for the Baa Baas as they seem to be trying everything to sell tickets. No doubt there's some fatigue from the local fans.
The first sentence of your 'edited' quote is, as a generalisation, inaccurate. England games at Twickenham this Autumn have been 'sell-outs'.
81,000 attendance on a capacity of 81,600 is - what 98% or 99%. Of those the empty seats were no-shows rather than 'not-solds'.
As for the Barbarians, well, I am sorry, but I think they are a 'yesterday' concept. That is why there is less demand.