When i'm searching for my keywords using google tools I like to see what my local results are for obvious reason. Sometimes I will find a keyword with good global results but the local results will show no data at all... Does this mean google just doesn't have any data for the local results? Should it really matter if the global results look fine? thanks.
How much of a difference? I've seen global results around 600 with no local results, but anything over 1000 seems to have local results. You can also try Google insight to compare the keywords http://www.google.com/insights/search/#
I'd go with local only to be honest, global are always random because you'd need to rank in every country, ie google.co.uk, google.co.il etc
I use the global because thier search will find you. You only have to be geo spacifice if you want to be.
It depends on where do you want to ranked or drive traffic?? If local search is not showing and global is fine than it's ok no problem go with it. But if you want get traffic on local (in specific country) than check local search and global search volume as well.
Google Search engine uses a very effective searching method by which the keyword is matched by the Results as much as possible through the available data.