At Microsoft, advertising has become an increasingly important source of revenue over the past few years. “Our search revenue encompasses both Bing [the Microsoft search engine] and also the revenue generated through a number of syndication deals on platforms which are powered by Bing,” explains Jose Luis Marti, director of Microsoft's Worldwide Online Credit Services (WOCS) treasury team. “On our platform, we provide both display and search advertising, and in both cases it tends to be customized based on our customers' and end users' preferences.

“It's our job in the treasury team,” Marti continues, “to ensure that the number of impressions and searches a customer purchases does not exceed what they can afford to pay, which is determined by their credit limit. If we assign a credit limit of $100,000 to Company X, then they should receive only $100,000 worth of impressions or searches. Once they reach that limit, they will not receive any more advertising until they have made a payment or they secure a higher credit limit.”