CainIV - 4:52 am on Apr 27, 2012 (gmt 0)
It's not just brand; it's also authority.
Brands have authority, but the reverse cannot be said to always be true.
IMHO authority is a measure of natural quality citations and links to your content over time.
Brand recognition has much more depth but includes authority, so authority - citations, links, is naturally part of becoming a brand.
If I were a search engine, other than inbound links I would be looking at signals like domain and whois, business ownership, memberships, associations, brand mentions, stickiness / bounce rate, community, social media, site security, transparency, authorship and likely a wide range of factors.