The clickTag variable is the IAB's standard for linking to external URLs particularly from flash banner ads. BannerSnack is fully compatible with clickTag, but from version 3.0 we made clickTag optional since a lot of our users are not familiar with it and have real problems understanding how and why should they use clickTag.
You should use clickTag if you really have to; here are the most important cases where the clickTag variable is a good solution:
Compiled Flash content, known as SWF, is not open to code inspections and/or modifications, therefore, whenever there is anything to change in a SWF file, you need to go back to its Flash source, make the modifications needed, then compile again. Also, there is no way you can tell what exactly does the script inside the SWF unless you actually see its source. This is the main reason why advertising networks still fear Flash ads.
They all love Flash, but with such limited control over what's in a SWF file, they need to be very attentive and have to manually analyze each banner's Flash source to make sure it's not a malicious script there, or anything else that's unwanted. Finally, publishers still need to measure all the clicks that run through their network in order to be able to use CPC, CPM or CPA conversions stats.
IAB (Interactive Advertising Bureau - an organization that helped the current Internet advertising standards establish) enabled publishers to have some control over the flash ads that run on their networks by inventing the clickTag variable. This standard allows advertisers and publishers alike to add a link to the SWF using plain HTML code, after the SWF content is compiled. For this to work, a piece of code needs to be added to the Flash source before compiling (that's something BannerSnack does automatically).
You can change the clickTag parameter in our standard embed code from null to a valid URL (Eg. http://www.snacktools.com). Once the clickTag parameter is named, the SWF banner (created with BannerSnack) will automatically cancel ALL external links found in the banner and replace them with the clickTag URL (this is done in realtime). The buttons that link to other slides within a banner ("go to slide" actions) will be still functional.
By making this option available, more and more advertising networks will start accepting Flash banner ads made with BannerSnack since we restrict the users' capacity to insert malicious scripts within these banners and allow publishers to control the external links.
All banners hosted on our cloud (the published embed versions) can be safely used by any advertising network/publisher. You just need to use the clickTag parameter and it should overwrite any other potential external link that can be found in the banner itself.
For more information regarding clickTag, or any partnership ideas please contact us.