Unfortunately, it looks like one of two things happened–either Brad didn’t specify which study he was referring to, or he did, and I just missed it. Sometimes it’s difficult to get every bit of information while liveblogging! :-)

You may want to check out Brad’s site, or perhaps even try communicating with him on Twitter (@bgtheory) to see if he can direct you to the study he was referring to. Hope that helps!

You mentioned that a study showed that coversion doubled without social proof. This is a bit surprising to me. Do you know where i can find more info about the study?

I like the idea about hidden captchas. Will begin using this moving forward.

Thanks
Henrik

I would caution people to take the “concise” advice with a grain of salt.

Take this case study from Conversion Rate Experts. The landing page they put together for SEOmoz grew annual sales by $1 million, and it is a (very) long landing page. Just something to consider before buying into the “short landing pages only” mantra.
You see long sales/landing pages on a lot of products, particularly in the “I did it and you can too” informational product niches as well as SaaS. The CTA needs to be clear and repeated about every page length, but this approach can work well