Arbitrage refers to the price difference between two different markets. In terms of online advertising, the arbitrage pricing theory is the valuation model that helps the market to determine the return on the security which is dependent on a number of factors. It is related to the price of the traffic and the factors that drive the price. In online advertising the arbitrage pricing theory is used to understand the relation between the arbitrage traffic and its price. The Arbitrage pricing theory is related to economics according to which two identical goods have similar price. If there is a price difference then it is called as arbitrage and the difference occurs due to a number of factors. In case of the arbitrage traffic, the buyer takes advantage of this situation where he buys the traffic at a lower price and then sells them at a higher price caused by the different factors. In case of an arbitrage condition, then one is able to earn profit and uses the arbitrage pricing theory to determine the returns he would get. Different factors are taken into account to determine the arbitrage pricing theory. If you want to make profit through the arbitrage traffic then you can buy it through a good online media company.