The Anatomy of a Perfect Landing Page

Nothing's wrong with starting out with some great guidelines, and then testing it to death.

    A short primer in unconstrained, high-dimensional, non-linear 
    global optimization (over time!)

    You can't do it.

Unconstrained and high-dimensional means that your search space is IMMENSE. Non-linear means that the optimal designs may be arbitrarily twisty, very small, fractaline and chaotic, and, most importantly, unconnected. Temporal dependence means that even if you magically find a good solution, it may fade with time.

Fortunately, we never have to do that because we use an incredible amount of prior design information (craft) to ensure that our search spaces are much smaller. This page provides an overview of that information (and even includes a call to test) which will hopefully put you somewhere in the neighborhood of a useful page and inform you of what direction to go.

If you "just had to test" then there'd be no need for art, science, literature, stock markets, language, thermodynamics, technique, craft, effort. Computers would have already solved everything (not that we would have ever invented them).

My opinion is that testing is vital because it's your only consistent, trust-worthy way to measure your value function (conversion rates). It's how you put a stick in the water to measure depth. That is only one tiny part of a complete solution no matter how important it is.

Also, they're using two different font weights and different kerning at different points. There is also a superfluous space in one of the bullet points.

The point? Have someone proofread your landing page, too.

I love it in theory, but the interface is kind of janky - specifically, I have lots of trouble with alignment, positioning, and lack of an Undo button.

But yeah, probably some real world statistics is better.

You could do the test yourself, and see if people are convinced by the image alone (even though the link only goes to for example the main page of verisign.com). I'm not sure verisign would be too happy about that, though :)

Results like these are highly context dependent, so don't expect that if you make the same change you'll necessarily see the same result. But seeing specific examples is great for coming up with test ideas.