If you have the ability to edit your page html and javascript, you can get more precise control by using the Munchkin tracking API.Use Javascript to read and parse your querystring...
I know about Get Multiple Campaigns in the REST API. The difference is getCampaignsForSource only returns campaigns that "can be used as input parameters into therequestCampaignfun...
I would really suggest that Marketo update and improve on this functionality. This is just not how people work. I might have the same image name (callout.jpg) across multiple campa...