I have a business problem. My business sells B2B software. We can use Google Analytics, etc to see how people get to our site and whether they download the free trial (desktop/server software). When it comes time to purchase, every once in a while the same person that downloaded comes to our online purchase page and we're able to attribute the sale back to the channel/ad/blog it came from. Most of the time though, so…
Have you tried a mapping based on IP address (this might work depending on the size of the business)? If the business is big enough, IP addresses should/would be registered to the company rather than a general-purpose ISP.