B.L. Ochman’s 12 Tenets of Social Media Marketing includes #5:
“V. Thy communications must pass the “who cares?” test.
Abandon ye all communications which are long-winded, formulaic, boring as hell and laden amidst superlatives and marketing babble.
Write down your concept in one sentence. Then ask yourself, and answer honestly, “So what?” If it still sounds like a good idea, proceed to re-write it over and over until it has not one extra word.”
He wasn’t thinking of landing pages specifically when he wrote this, but it applies 100%. If you landing page does not answer So What in a couple of seconds, the money you spent to get someone to see that page was just wasted.
And remember, Ian says that every page is a landing page in his free internet marketing book Conversation Marketing.