> Don't just do something because everyone else is 
  > doing it – do something because it makes sense.

I can't speak for the particulars of gradients or drop-shadows, but if two-sentence landing pages with an obvious call to action get signups, then it makes sense to do things that way.

I guess the inverse of the advice is "Don't refuse to do something just because it's trendy -- base your choice on whether or not it makes sense."

I agree, for the most part.

However, I want to note that by following an effective trend, the "two-sentence landing pages with an obvious call to action" in this case, isn't there a chance that one might be missing an even more effective/efficient way of doing things? Sure it works, but does it work the best?

   >I guess the inverse of the advice is "Don't refuse to do something
   >just because it's trendy -- base your choice on whether or not it
   >makes sense."

Also couldn't agree more, I think there is a really fine line between innovating because you think you can do better and innovating because you want to avoid the trend.

*Edit for formatting, I am new here.

I do find it ironic actually and that is why I like that one. It is very easy to be trendy and I think you know you are onto something big when it easily breaks them.

Who started that trend?