Simsi - 6:36 am on Oct 4, 2012 (gmt 0)

Can anyone qualify exactly what makes them think their site is regarded as "An Authority Site"

One strong indicator IMO is when a significant number of visitors arrive from searches that include the brand name or domain name. But I'm not convinced that's how Google views it.

As a "user" it's pretty easy to spot an authority site by the content. For (an ecom) example, if I'm buying a new widget I can usually find a stack of sites that describe it as per the brochure, tell me whare I can buy it and where it's cheapest etc. But the one where the site tells me if I buy widget A it will fall apart in 3 months, that widget B is known for blowing up in my face and widget C is actually the best option despite looking like it went out with the 70s, now that's the authority site.

Problem is, the only way G can know that is by understanding the item being talked about or by measuring user behaviour and that's a bit of a moot issue. Hence my comment on brand name searches.