When running online advertising such as paid search campaigns, it can be extremely easy to see how it is working online, by placing conversion tracking on your website and therefore seeing exactly which keywords are generating online sales, making it very easy to calculate your ROI.

However, when it comes to measuring the affect of online advertising on offline sales it can be extremely difficult to see a direct correlation.

The Internet is a great place to conduct research about what you want / need and can be a safe and easy place to purchase those product(s), however some Internet users may be perturbed by purchasing online or paying delivery costs etc. so may conduct their research online and then physically go in store to make their purchase.

This is also the case for larger products such as cars for instance, as many drivers may go online to do research about their favourite vehicle but are not likely to purchase one online and would therefore go into a showroom to test drive and then possibly buy the vehicle.

Unfortunately it is nearly impossible to track this kind of conversion and therefore Google has conducted a study, partnered with an outside firm, to test the affects that online advertising has on offline sales in order to provide AdWords customers with some evidence to show that advertising online can have a positive affect on offline sales.

They tested the affects on selected test markets across the US by saturating the selected areas with online advertising for particular stores and their products and testing the affects against the control markets.

Overall the results were positive with some advertisers seeing as much as a $15 return for every $1 spent on online advertising from in store sales.

Unfortunately the video that Google has released is very animated and only highlights a few of the positive examples.

It would be a lot more beneficial for advertisers and make the findings much more compelling if they had released a formal report, but it does give us food for thought.