Both virality and direct response advertising are areas where getting the details right are critical. One element in both chains is the page on your website that a new user lands on (either from a friend invite, or from an ad.) Many developers don’t sweat the details on what they regard as “aesthetics”. Many designers focus more on making a page look good than getting users to do what you want them to.
Here is an ecellent “how to” that breaks down what a good landing page should look like.
(thanks startup digest)