Why is conversion testing important? Well, get 12 experts in a room and you'll not find a great deal of agreement on what is right and wrong with a web page.
I will add that, had we all been given access to analytics, we would have come to some more common conclusions. Measure and test.
For the Online Service, the home page is a Landing Page. It's job is to sell the trial. Here is a good example of an effective home page, complete with the opinions of fourteen smart conversion marketers.
The folks at CrazyEgg have a wonderful summary of the five website formulas found in my book.
Brochure Site
Consultative Site
Publication Site
Online Store
Online Service
Read this and you can skip chapters 3 and 4.
The "sales letter" is a style that is used in particular situations to convert. You may never need one. However, the four P's of copy are a golden nugget in this article. They should guide your copy in any landing page situation, sales video, etc. They are: PromisePictureProofPush
@CrazyEgg If you asked 14 conversion experts what they consider important for increasing the performance of a website, you would learn a great deal in a short time. This article delivers, with some very smart people (including me) weighing... for you.
I will add that, had we all been given access to analytics, we would have come to some more common conclusions. Measure and test.