Yet another common option for A/B-testing a page is to associate the variation with a shortcode. The shortcode is then added to the original page and the content is replaced dynamically (either at the server side or at the client’s).
Nelio A/B Testing does NOT do this either for three main reasons. First, from a usability point of view, we believe it’s too complicated and ends up messing your original page with unwanted code. Secondly, this limits a lot what you can change in the variation —you’re basically restricted to changes on the body of the page (i.e. where you can type the shortcodes). Finally, depending on how this solution is implemented, you may still suffer from the caching or redirection problems described here.