Pippin Williamson blogged about why he believes competitors should be a source of motivation. I absolutely loved it:
One of the best changes I have made in my professional career is adjust how I look at my competitors. I look to them as sources of motivation and I applaud the magnificent work that they are doing, even when it directly competes with the products I am trying to create.
That change alone has made me a much happier and much more successful person than just about any other change I’ve made in my business. I worked hard to give up the jealousy and instead appreciate the great things that others are doing and then analyze it to see how I can take what they have learned, and what they have built, and apply it to my own products.
That's just one bit of this outstanding post.