One of the most difficult things for companies to do as they move onto the Web is gauge the costs and benefits of advertising on the Web. Many companies have developed new metrics to evaluate the number of desired outcomes their advertising yields. For example,instead of comparing the number of click-troughs that companies obtain per dollar of advertising, they measure the number of new visitors to their site who buy for the first time after arriving at the site by way of a click-through. They can then calculate the advertising cost of acquiring one customer on Web and compare that to how much it costs them to acquire one customer through traditional channels.