What do you have learned through A/B Testings?

[white knight]

The most important lesson which I got from A/B testing is that learn from mistakes.

PPC campaigns can be tricky so choosing the right keywords ad excluding negative keywords.

Pitching sales to the customers visiting in the landing page is have to be carefully handled. I always prefer a landing page, a product description page and a sales page. Three steps is more than enough if you do good.