I've always simply targetted the exact keyword I want to rank high on. I've heard people talking about distributing your anchor text to variations on your main targeted keyword. So if you wanted to rank high for "blue widget", you do most of your incoming anchors to "blue widget", but then also include some like "cheap blue widgets" or "buy blue widgets". If you weren't concerned with ranking high on these variations, and only wanted to rank high for the main keyword, would it still be worth it to vary it like this? If so, what percentage do each in and see the best results on the main one? I've had success only targeting the main keyword, but wanted to get others input on this.