adserving

How Ad Serving Works – Mobile vs. Web Environments

The most popular article on this blog is one of the very first ones I ever wrote – How Does Ad Serving Work. What I probably should have titled it though was How Does Ad Serving Work on the Web, because there are a few important differences when you’re talking about the mobile ecosystem.

Server Redirects vs. Client Redirects

For the most part, it comes down to the interaction between a client and a server – in desktop environments, the user’s browser, or the client in technical-speak, does most of the work fetching and redirecting information, which is ideal for lots of reasons. For one, redirecting the client gives each platform in the ecosystem the ability to drop or read a cookie, which helps with downstream conversion tracking, frequency measurement, and audience profiling. Secondly, it facilitates client-side tracking of key metrics like clicks and impressions for billing purposes. Client-side tracking is the preferred methodology for advertisers because it measures requests from a user instead of from a server, and is therefore a more accurate measure of what a user actually saw.  This process requires more work from the browser, but that’s OK because high-speed connections and unlimited data usage is pretty much the norm these days for home and office connections.

Desktop Ad Serving Sequence

In mobile environments though, connection speeds really matter. Many users are on slow enough connections that if the browser or app was responsible for fetching the ad the way it does on desktop connections, the user is likely to abandon the page before the ad finished loading. Because of that, you often see more of the work being done in the cloud for mobile ad serving, independent of the client. So instead of the browser calling a server, and then being redirected to another server, the browser tends to call a server, which then calls other servers, which can talk to each other through the ultra-fast fiber-optic landlines instead of the cellular network. (more…)

Limitations of IP-Based Geolocation

This is the third article in a four part series on Geotargeting. Read parts one and two.

Despite the complexity and scientific approach of IP based geolocation identification, there are well known limitations and inaccuracies with the current methodology.  While geolocation data is usually extremely accurate down to the state or city level, as services demand more granular data, many of the current geolocation services start to break down.  The loss in overall coverage is quite small, but accuracy can be another story.

Server Location vs. Machine Location

One of the more challenging aspects of IP based geolocation is that often times, geolocation services end up using the location of the server on which that IP is accessing the internet, not necessarily the location of the end user’s machine. So however impressive you may have found the diagram in the last article on IP triangulation, the method may end up targeting the wrong location.  The classic example of this known within Ad Ops circles was AOL dial up service, which in its heyday represented a large share of internet users.  AOL’s servers were all physically located near its headquarters in Virginia, so every IP address hosted by AOL, was often shown to be located in Virginia, even though users were spread throughout the country.  Today, this is much less of a problem because most consumers have a high speed connection serviced by a locally hosted ISP, but it exposed the problem in a big way at the time.

That said, local ISPs network routers, while usually quite close, are frequently in different zip codes, so while coverage remains high for most IPs at a granular level, accuracy can be less reliable. When researching this article from my location in New York City, most services were more than 7 miles off my actual physical location, perhaps a small difference in much of the country, but an enormous gulf in as dense an area as Manhattan.  Every service however was correct about my location at a country, state, and city level.  You can check your own location on MaxMind’s demo page, which incidentally, was one of the more accurate services. (more…)

How Does Ad Serving Work?

Interactive ads are everywhere these days, but when it comes to the technical process of getting an ad on the page and how publishers and marketers verify it delivered, not many people outside ad operations can explain what actually happens in detail.  Read this article though and you’ll be one of them!  Below I’ve detailed step-by-step how a browser gets from the initial call to a publisher’s website to the final ad creative, and when and how each party counts an impression.  You can view a diagram of the ad serving process at the bottom of this post – the numbers in the text refer to the steps labeled in the diagram.

So, without further ado – (more…)