Google Predicts and the effect on SEO

Hi Guys,

I know its been around for a while now but when entering a word into Google it will give you other search terms which may be of interest/relevance.

Sometimes terms come up, which you may have not looked into and even if you have looked into the term with googles keyword tool you may think the search volume is not enough.

But surely google is adding these terms to the dropdown because it DOES have a high level of search compared to other terms in that industry???

Basically is this a good way of locating keyword terms which will 100% perform?

I like to select a range of the drop down terms and check out the results generated number and top 3 sites.