You might care to look at this as well:
http://www.google.com/insights/searc...3%AD%22&cmpt=q
And see how it isn't likely to be searched for on its own, but rather as part of multi-word terms e.g:
isso aí
e aí
Its one massive "hole" with google keyword research stuff, that results are for all searches containing that keyword, not just the exact match.