these results are determined as the expert or aurthority sites/pages on a specific matter, generated by an heuristacal assessmest of 'best of fit' on all algo vairable conditions.
Algo vairables are numerous, i.e. 100+ (only AJ's team know the exact amount and the interplay between the conditionals). Main one's to look out for are:
on-topic linking from related sites content matching - massive area, involve's so many other smaller variable's. content distribution across site, and inter-content distribution accross intra/inter sites!
I think i have got my knickers in a twist on this one.
Editorial, not expert - then the answer is yes, but you may find in certain cases where the topic is not covered by a paid (whether sponsored, ppc) listing, then the computers or editor list an appropriate site as a freebie filler, until someone wants to pay for it - then watch the freebe disappear.
This same site has also recently been added to the 'pull down' menu where i beleive you do pay to be listed.
I find it too much of a conicidence that they start paying to be listed and then appear in the 'editorial' answer section.
Sometimes it pays to go to the source itself. On the Ask UK site if you click on the "i" icon you find Ask's explanation. Basically, it says that they are sites that the editors found "particularly useful" and that "advertising partners may sponsor some of these results." It also gives a link to Ask's editorial policy.
Ask advertising calls these "Answer Links." More info here: