In this article Anne Holland suggests to focus on the email test that will give the biggest bang for your buck. Here are her top two suggestions for testing landing pages and email:
1) Test headline copy. And once you have picked the perfect wording for your offer or newsletter lead article headline, don't get creative with it. Keep the exact same words in your subject line, email headline, and landing page. That way the recipient's flicking, restless eye will immediately see clear visual cues that he is in the right place.
This may not be easy because you have a different amount of space in each -- especially short subject lines vs. possibly longer landing page headlines. But if you use the exact same words as the foundation of each, you'll probably get better results than if you had not.
2) Remove distractions. Pare your landing page to as few visually distracting items as possible so that each person who clicks through will focus on the path you want him to take. This may mean eliminating extra columns, sacrificing spare navigational bars or buttons, and cutting unrelated graphics. The fewer distractions, the more chance visitors will spend more time on the page.
If you have a hotlink on a landing page, an ad, or anything else that's not what the visitor clicked through to see, then it should be there for a specific reason. And if it's there for a specific reason you should be measuring its value. Does your organization make more money in the long run if that extra element is there?
Read the full article here and find out how to run these tests if your web department can't help you. She offers some really great tips (like using blogging and survey tools as low-cost alternatives)!