Thanks to everyone who sent in suggestions to improve our new Knowledge Store. The most important thing everyone mentioned was to "move reviews higher up!" So, we redesigned the page to bring quotes from reviews above the fold. Here are five more lessons we learned:

1. Store buyers will definitely use a viral "Tell a friend about this product" tool if you give it to them. In fact about 20% of our visitors use this tool. It may be particularly useful for the business marketplace where some employees need to get permission to make purchases.

2. However, the viral "tell a friend about this product" tool only gets a high response when the form is right on the product page. If visitors have to click on a link to be able to use the tool, far, far fewer of them will do so.

3. eBooks created using executable files (.exe) won't work as viral sales tools for the business market because most companies' email security systems stop those files from entering. I love the idea of systems, such as RoyaltyLock, that allow visitors to download tantalizing samples including offers to pay to "unlock" the rest of the document, especially because it can encourage pass-along sales when they send the free sample on to their friends. But in the B-to-B marketplace you're stuck with PDF, Word or HTML for now.

4. Never write online marketing copy in a void. You can't know if it will work until you see it posted in the store. Suddenly phrases that looked great in Word just don't fit the space or format. Also, set up a schedule to revisit copy a week or so after it's posted. Unlike printed marketing materials, you can change copy online ... and with fresh eyes, you'll almost always spot a word or two you can tweak to improve sales.

5. Sales conversion rates are higher if you reference where the visitor is coming from. For example, if you are running a marketing campaign in Cars.com for your car book, everyone who clicks through should see something saying "Welcome Cars.com visitor!" or references a special discount available to Cars.com members only. (Plus, as an added benefit, your affiliates will love you.)