How will VBSeo help me?

I have a vbulletin board (2yrs old) with about 68.000 users, i have about 850.000 visits monthly and my main niche is currently ranked number 1 in google and yahoo, i also use adsense so can someone roughly tell me how'd i improve in buying vbseo?

regards

While you already rank for your main terms, you have to fully release the power of the long tail.

With vBSEO, optimizing on a page by page, thread by thread basis will deliver thousands of visitors from thousands of different search terms:
What is the Search Long Tail? - vBulletin SEO Forums

We also include an AdSense optimization feature, which can also be enhanced using our Relevant Replacements feature.