Here's a campaign that has scratching our heads. How's it work. What's happening in the background. Anyone have a theory? Because we have a few. H/T to Jason Levine.

• The site says it serves up an ad “at home” so maybe it’s using the master Google cookie to identify the location of two machines that at some point use the same node to connect to the internet? That would make some sense. Few people know about the master cookie… except the NSA (natch!). 
• The whole thing could be a ruse, and the content you input is randomly served into Google ads. If that’s the case, they know that people rarely travel farther than 50km from their home base. That would allow them to serve up the ads based on geo-node, postal code, or IP location. It would be random, but deliver enough of them and you could increase the likelihood that an ad is seen.
• Or, the likelihood of someone actually seeing the ad might be incredibly low… and the fact that they offer up a Twitter or Facebook alternative is the real objective. It would be interesting to see how many people do that.
• It could also be using a behavioural targeting cookie. For example, Zappos makes extensive use of behavioural targeting. AND when you share an item, add it to your wishlist, or share that item with someone I think it captures that info and stores it in the cookie. Maybe IKEA does the same thing. So, cross-referencing several persistent cookies might allow them to cross-target to the IP or machine mac address.

Try it yourself, and let us know what you think they're doing. IKEA Share the Bathroom - IKEA.