I hope im understanding your question correctly, im responding only regarding landing pages. Firstly relevancy, its important, text and keywords within the text on the landing page, dont make up the page mostly of images. Meta tags, alt tags. Have the landing page make sense to the visitor, dont confuse them, make it easy for them. A fast loading landing page, obviously down to your hosting and what you put on your page.
* H1 and H2 should contain the keywords you are bidding for. * After that, there should be a series of bullet points telling about the product and including the relevant keywords. * All the relevant images should have relevant "alt" names, because google cannot read the images. * All the irrelevant images such as icons and all should have irrelevant alt names only! You can get fine details on quality landing pages, in PPC Classroom.Its being given for free. I have gone through the course, very well written with amazing members area.Its really worth reading...