Retargeting is a fairly simple concept. The goal is to turn potential customers into actual customers by bringing someone to your site who has shown an interest in your product or service. The practice has gained a following in recent years because it consistently drives sales and revenue. Increasingly, due to strapped media budgets, marketers are relying on retargeting to boost the bottom line. But here's the truth: While everything you know about retargeting is not wrong, it is likely incomplete. When most people think of retargeting, they think of Site Retargeting, which is the practice of targeting users who have already visited your site in the hopes of getting them to return. For example, Amazon can drop a unique cookie on your browser when you look at a pair of shoes on its site. If you don’t buy the shoes, but then continue to surf the Web, a retargeting platform connected to an exchange using real-time bidding (RTB) can identify you (via your cookie) as someone who visited a specific page on Amazon. Amazon, meanwhile, will have already entered a bid that tells the ad exchange how much it’s willing to pay to serve you an ad for the shoes you looked at. Amazon will likely bid high, because you are a valuable potential shoe buyer that is clearly in-market. Basic Site Retargeting of this sort is widely used and can be an important tool for marketers. But lost in the discussion are the six other types of retargeting, some aimed at persuading former visitors to return to a site and others that focus on acquiring new customers. The most exciting of those six other types of retargeting is Search Retargeting, which boasts significant untapped potential for attracting new customers based on the search terms they've entered into Google, Yahoo, Bing, or other search engines. At the most basic level of Search Retargeting, a company uses search data to target potential customers and bring them to their site for the first time. For example, users who search "speaker sale," and then browse around the Web might encounter display ads from an electronics retailer selling speakers. The key here is that the user never visited the site of the electronics retailer. The targeting was done strictly on the search term, making it possible to acquire a new customer. Targeting based on search terms is uniquely effective — just ask Google — because search terms signal a user's intent. Given the recent rise of these new types of retargeting, one might think that traditional Site Retargeting has reached a mature, non-changing, static stage. However, dramatic new approaches are promising to overhaul even Site Retargeting. Traditional Site Retargeting has focused on tagging sections of your site with cookies -- and this even got clever enough to show the last product you visited. However a new approach doesn’t aim to hard-code these segments by dropping multiple cookies. Rather, a “programmatic” approach aims at pushing all the granular details about a users actions into a cloud-based user profile. By keeping all user activities server-side, marketers can essentially query their site visitors in real-time and make up highly granular segments on the fly. We call this practice Programmatic Site Retargeting (PSR), and it’s sparking a revolution in how marketers optimize their RTB buys. By keeping all browsing and behavior data in the cloud, markers can examine each user's actions and determine the likelihood of different types of users to convert. This "visitor score" can then be used to inform the RTB bidding – reducing bid prices on those users not likely to convert and increasing them for high value customers. It works incredibly well because robust PSR data creates a sophisticated picture of a user’s value to a site, based on a wide range of data points including pages viewed, referral data, shipping address, environmental factors (time of day, day of week), items in cart, customer profile, and many others. PSR transforms Site Retargeting from an intelligent guess into something much closer to a science. For advertisers, this means fewer wasted impressions and greater returns.