The objective is sales or more specifically to increase sales and decrease marketing expenses. On the most basic level, you want to measure sales, sales per visitor, cost per visitor, and conversion rate.

The buying and selling of goods on the Internet. Certainly the most cost-effective way of doing business because it represents the lowest overhead possible: no building to rent, no products to stockpile and the lowest cost form of advertising in the world (other than word of mouth, of course). This cheapest form of Internet advertising (free!) includes optimizing your site