In August 2005 was the first time I saw "According To" Google results show up in the search results. Since then, they show up for very specific queries.
I spotted an interesting thread, where a webmaster asked why is his client showing up in the Google "according to" results. The thread is at Google Webmaster Help forums, and the webmaster showed that his client ranks for the search query octopus top speed. Here is a screen capture:
The webmaster asked a valid question, i.e. how did this happen? He said:
I am interested to know how this data is sourced and how we can improve the A-Z-Animals.com website so this happens for all the animals listed on the site (over 350 animals are listed with comprehensive fact lists) as the client has worked extremely hard to source reliable information for the site which will be extremely valuable to users of Google search. Or is it simply a case of given time Google will source other information from the site assuming another source isn't being used?
Autocrat, a top contributor in the forum says he really doesn't know exactly how Google shows or complies these, but he offers his two cents:
Your client does realise what a recommendation and acknowledgment that is, right?
Chances are that it''s automated/algorythmic.
Its probably done over time and based on various factors - possibly things like time, references, quotes, links to the information etc.
The only advice I can offer is for your client to keep on doing what they clearly excel at!
This may be similar to how Google Definitions works, but I would just be guessing.
Forum discussion at Google Webmaster Help.