Every business site -- and many organisation sites -- have what a Most Wanted Response (MWR). For many business sites, the purpose is

1. to sell a product,
2. to have the visitor go through an affiliate link to buy a product on another site, or
3. to generate contact information for a future lead or follow-up.

For organisations, success may be measured in memberships or subscriptions. Whatever your MWR, you must work to optimise responses.
Good sales pages result in a high ratio of sales to visitors -- called the "conversion rate." A good site might have a conversion rate of 3% to 5%, some higher and many lower. Over the past few years, marketers have developed the art of increasing the conversion rate. This is especially important when you are purchasing Pay Per Click (PPC) ads to drive traffic to your site. Your profit is closely related to (a) the cost of the click and (b) the conversion rate of the "landing page". That is, the sales page to which you direct interested shoppers.
For stores that sell many products, the techniques to boost conversion rates are similar, but with some variations.

To scientifically and systematically increase your conversion rate to the maximum, you must carefully track sales percentages for each product your sell. Then make incremental changes to the landing page or the order system and see if the conversion rate rises or falls. Over a period of careful study and change, you'll maximise your sales. Here again are the steps you'll go through:

1. Set up an ordering system (e-commerce capability)
2. Create a landing page
3. Boost sales on your landing page by testing