The three Is

Everything you read or write should fall under one of the Is:

1. Interesting
2. Informative
3. Inspirational
   

The most basic requirement is that it is entertaining, amusing, or otherwise interesting. Even if there's nothing else useful about it, it can still be worth a read if it's interesting.
The second possibility is that it's informative. Information is always useful. Unless it's disgusting. In which case it shoud be avoided.
Finally, it should be inspirational. There is so little in this world now that is great, anything that rebels against that should be praised.
(Coming soon: the 3 Bs!)