When you start a business, you're looking if it already exists. Write down these words and phrases you are looking for your competitors. Make the same with you friends and colleagues: Tell them to have a look for this or that and collect their entires. That are the most promising key words for your startup, believe!
Of course, the old back link way work, but google also started screening relevant site content, comparing with your competitors, etc.
Another big issue is that they have a look at your website structure. All pages should note be deeper than 2 pages away from your start page.