Do 2 Goods Make a Great?

As usual, Seth Godin adopts a strong position: good is much worse than great. I am reminded of Spinoza's famous claim (from 1677) that "all things worthwhile are as difficult as they are rare" (Pt. V, prop. 42). If good isn't nearly as good as great, it seems to follow from this claim that it's better to perform 1 great act than 2 (or 3? or 4?!) good ones. Is this true? I guess Godin would say it has to. If being great is what's going to count, then it's worth almost any effort to be great. To be good, then, is not a winning strategy. Does this mean it's not winning in the long run? But, aren't there many "good" companies out there. Isn't the market full of them? Maybe he means that the most successful companies focus on being great. Isn't this then a tautology? Great companies are great? To be sure, being great is great. And in a competitive situation, greatness will distinguish you from others. Will greatness get you noticed? Will a potential customer or client even know what great is? It's compelling to think that greatness is important. And it seems intuitively obvious. Who doesn't want and try to be great? But, is it risky? Does trying to be great and failing result in goodness? Or in something worse? Is it worth the attempt?