Stockholms Stadsmission is a social charity that works to help the homeless, among other things. We helped their advertising agency Garbergs and banner producers Banner Boy to produce a rather elaborate system that allows sites to provide shelter for homeless banners, and in return get their name in the banner and on a top list that rates sites for both shelter time and number of clicks. The banners also display a heat map for where they’ve been clicked, with the actual coordinates of each click received. Clicks lead through to the donations page for Stockholms Stadsmission.

The project provided a series of intriguing technical challenges. Since the site name in the banner is dynamic, we wanted to ensure we had the ability to shut down foul language. We also had to track how long the banner had been up in order to provide an accurate shelter time ticker, and the tracking of click coordinates for the heat map per site and per format was another data point. Add to this that sites like blogs and corporate sites will want to use normal flash embedding to display the banners while media sites like major newspapers need to enroll the banners in their ad serving systems instead. We opted to produce separate solutions the two site categories:

Personal & corporate sites

On the campaign support page, linked from the donations page, the user enters the site name they want displayed in the banner. This name is stored in a database and assigned an id. The id is added as a flash var into the embed code provided with each banner format. Each time it’s loaded, the banner asks our server for the name connected to this id. Should there be an inappropriate name or phrase, we can delete it from the database.

Ad serving systems

As we can’t provide the name id through a flash var in the embed code for this type of site, we instead made a custom set of banners with a movieclip on the stage that has a name full of zeroes. When the user enters a name and it gets assigned an id, we use PHP bitwise operators to change this name to the actual id in a copy of the SWF file right on the server, making custom SWF’s immediately available for download. On load, the banner looks at the name of this movie clip, interprets it as an id and constructs the correct request URL to our server which responds with the name.

For both banner types, clicks trigger the target link as well as a call to our server with the banner id, format and pixel coordinates for the click. On load, they receive not only the name but also the last 20 click coordinates so that it can display an accurate heat map.

In order to ensure that the shelter time ticker in the banner is correct and that the banner is indeed still hosted, we have a timeout of 48 hours. If we see no requests for a particular id in this time, the timer is reset. This allows some lenience for sites with very low traffic or sites with the banners in rotation.

Since every banner load creates a call to our server, we could not have done it without kind help from hosting providers Space2U who host the database and download interface, and Qbrick who host the embeddable SWF’s.