How do I improve the ranking of a site, which already receives huge volumes of traffic?

[underscorelive]

I have taken over the SEO campaign for one of our largest clients. They already receive over a million visits a year due to the brand itself.

However, I'd like to start targeting some new search terms to diversify the incoming visitors.

Any advice on this type of situation, beyond traditional SEO best practices?

Thanks in advance!

[underscorelive]

Thanks guys - I appreciate the question is vague but I'm afraid I can't give away too much at the clients' request

[DavidKonigsberg]

Longtail quality content creation is always great for strong sites but without knowing more about the site its hard to say

[TheeDigital]

Underscore,

Without knowing your brand or your signal, it's kind of hard to answer that question.  However one suggestion we would have is control the social signals as much as you can.  Google Authorship and Google circles don't have an SEO impact currently, but they do affect click through rate so make sure that you are on these channels and own them.

Also don't forget about Twitter and Facebook, these services are private and closed off from Google for the most part, however they do still show up in search for your brand name and definitely can be used to crowd source your other keywords.