Some more tips are:
1) To have successful marketing campaign, your selected keywords, product and audiences must be in sync with the content in your landing page
2) You must make sure that your landing page is clear and precise, so that when a visitor landed on it, he does have to guess what it's all about.
3) Your headline is the first thing you must look at in your landing page. It can either attracts or repels your visitors
4) Benefits are the keys to successful landing page optimization. You start by going through all the benefits and write down the major ones.
5) People will be wary if your site looks sloppy. Therefore, it is important to win your visitor's trust by having a clean and professional looking landing page. Here are some tips to get your website looking clean and professional:
* Arial or Verdana Fonts, 10 to 14 size
* Keep your background bright and text dark
* Have no more than 3 columns
* Don't change your link colour, keep them in standard blue
* Your landing page must contain the images of the product that you are promoting
* Check your content fully for spelling and grammatical mistakes