YouTube - How Important Are Graphics to Sales Copy?

Years ago, I used to think that fancy graphics and headers were all you needed to sell a product online. After all, when you go to the store, that's usually all you see in front of you... whether it's cereal boxes or software boxes. But then one internet marketer showed me the truth... he displayed two sales letters side by side. One contained sales text and no graphics, the other contains graphics and no sales text. Which one do...