What would you say the top 5 or so mistakes most new webmasters make are?

For me i would say it goes something like this...

1) Not treating porn like a business
2) Using 'public domain' content
3) Copying others work
4) Trying to do everything at once
5) Not listening to others when they have advice to give

Would you folks say that was a good list to start out with? Is there anything you folks think should be added or removed from the list?

Regards,

Lee