There are hundreds of variables on landing pages that can be tested (and thousands when tested in tandem) and used to influence visitor conversion. With PPC prices rising and SEO competition increasing daily, developing compelling landing pages is perhaps the most important way to keep costs low and the return on your advertising spend at levels that will keep you in the black. Many marketers are taking aim at this initial user experience and testing elements that are widely seen as the most influential aspects of successful landing pages - here is a list of 25 such elements that should be taking into consideration with any landing page review.