Keyword research ought to be one of the first things you do when setting up an online business. Heck, it's one of the first things you should do when setting up any business nowadays. Even if you don't have a website of your own, your business should be online (think Google Places, Yelp, Amazon, eBay, LinkedIn, Twitter, and Facebook, to name just a few).
Even if none of the above matters to you, keyword research still matters because you want to mould your marketing message and all marketing materials with the keywords that will pre-sell your products and services.
Having said that, once many folks convince themselves that they need to do KW research, they ultimately fail by either doing it wrong or waiting for the perfect set of keywords.
You may have heard this term before: Analysis Paralysis.
You get so caught up in the data, go on tangents, analyze using multiple tools, all of which give you conflicting information.
Below is a link to a pdf I picked up from a friend in the industry, written by two pretty smart guys. In it, they show you how they do keyword research. It's a simple formula. You should check it out. You may find that it's perfectly suited to you and your situation.
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