What are tier 1, tier 2, tier 3 keywords (pages)?

[VinceWicks]

I am seeing these terms, but for the life of mine I can't understand what they are. Could anybody explain that in layman's terms? Thanks.

[ThompsonPaul]

In addition to Vahe's suggestion, it's possible the terms being used refer to what is also frequently referred to as "the long tail" of search.

Tier 1 or "head" terms are search terms with both extremely high search volume and very high competition Tier 2 or "body" terms have lower search volume and competition, and tier 3 or "long tail" terms are those which are so specific they are searched much less frequently, but also there are considerably fewer sites competing for their traffic.

Example:
tier 1 head term - "SEO"
tier 2 body term - "ecommerce SEO specialist"
tier 3 long tail term - "SEO specialist for WordPress in Seattle"

Note it's not just the # of words in the term that determine it's tier, though usually longer terms will be located farther down. It's more the search volume and amount of competition that determines the classification.

There's lots of info on the long tail of search here at SEOMoz and the web in general if you want to get a deeper understanding of it's value.

Paul

[Vahe.Arabian]

Hi Vince,

I think they refer to primary, secondary or tertiary keyword targets used for the page; primary being the main keyword used to optimise the page.

Hope this helps,

Vahe