The question of how online advertising is driving offline sales is not a new one. The interaction between on and offline and across devices can be clearly seen when studying the role of Google search in a journey to purchase.

Google’s 2013 Mobile Planet research uncovered that after performing a location-based search on their mobiles and deciding to purchase, 27% of Australians will choose to switch to their desktops to convert, and 31% will convert in a brick and mortar store. So even when beginning a journey to purchase on a mobile, Australian consumers still prefer to go to a store to complete their journey to purchase

So how can we properly attribute the role that, say, a geo-targeted mobile or paid search ad and a Google Maps listing had in delivering a purchase that was finally made in store?

Technologies that have come out of Silicon Valley in the past couple of years can help us work towards finding the answers such questions. The recently out of beta Google Universal Analytics provides the ability to track a user across devices and platforms (web and apps) where a unique user ID is present. It even allows marketers to tie this online journey to off-line touch points, again provided that we still have that unique ID, through uploading CRM data into the Google Universal Analytics platform.

Apple’s iBeacon, in addition to providing an alternative to NFC for proximity marketing, will allow brands to connect a user’s in-app activity with that user then entering a store (provided that the user has accepted to receive iBeacon transmissions through the brand’s app). The data gathered on the content viewed by the user in the app could even be used to generate targeted offers, pushed to the apps once the customer walks through the doors of the real world store.

Sounds pretty exciting doesn’t it? So is 2014 finally the year that we’ll be able to close the loop and connect a user’s journey on and offline? Unfortunately there are still huge challenges to be met.

Firstly, both of the above solutions require an action from the customer, whether that’s a form of login to get a unique ID to track, or accepting to receive transmissions. Technology has just not yet found a way to cookie an actual person and follow them round everywhere they go in their 4 dimensional world.

Where brands can offer strong incentives to logging in or accepting transmissions, this difficulty can in some way be overcome. However there is still a proportion of the population that is deeply suspicious of offering up this kind of data to marketers and just won’t play ball.

This leads me to my second point; the complex issue of privacy. This can currently be handled by ensuring that proper permission requests are in place, however there is always the risk that future legislation will make data gathering more difficult, following on from the fondly termed “cookie legislation” in Europe.

Thirdly, until all TV is watched on the internet, all print is viewed on a tablet and all customers everywhere interact digitally with each outdoor activation that they see, there is still a large part of the journey that cannot be accounted for in this way.

Finally, we can’t ignore that for corporations operating on a large-scale, implementing new processes and technologies such as these takes a substantial investment in both time and money. If the implementation involves rolling out changes to till systems or installing technology in a large number of stores, this just cannot be done overnight.

So 2014 may not be the year that businesses finally manage to measure the true value of their online advertising, but these new developments will certainly spark wider discussions about attribution and online/offline conversion funnel optimisation.