May13Written by:Jacques van der Hoven
Thu, 13 May 2010 23:13:52 GMT 
For MedicalAid.co.za we were asked to build an advertisment system which would deliver adverts as well as track impressions, click-throughs and finally to draw reports on all of this including click-through ratios. After some initial research we came across an article written about Yahoo's method of doing just this, which we found to be the best solution in terms of making sure each impression and click-through recorded is unique.
There are three main parts to this web application project and they are 1) a component to deliver the advert on each page, 2) a component to record the impressions and click-throughs and 3) a component to view the reports.
Since the MedicalAid.co.za site is built on the DotNetNuke Content Management System (CMS) platform the components were built as modules the most intreaguing of which was the component deliverying the adverts. According to the Yahoo approach one needs to consider making every advert image cacheable to ensure better performance of the site, but at the same time you want to ensure accurate readings of impressions and click-throughs. A Javascript approach is used here to dynamically add image elements to the page including a unique number as a query string after the full image URL. We also made use of custom extensions for the images such as Impl, which when requested by the Internet Information Server pushes the request through to our custom handler. The custom handler is responsible for recording the impression before returning the real URL to the image or page.
In this way we're able to keep accurate readings for MedicalAid.co.za and their customers.