What is the most representative way to measure the impact of a digital signage deployment?”
There are a number of ways to measure the impact when it comes to new deployment of digital signage but few are as accurate as measuring sales and foot traffic.
One way to measure the impact of a new digital signage deployment would be with analytics. There are a number of vendors putting out analytical software measuring things like dwell time and foot traffic. These numbers can be cross-referenced with numbers before your digital signage was implemented to give you comparative data. Additionally, personalized data can be scrutinized as well. Is there an increase in repeat and new visitors? The data for new customers can be quantified and compared. Outdoor digital signage will more than likely have a greater impact, as everyone who passes by your location will see it.
Another, and probably more obvious way of measuring your new digital signage, is comparing sales data. Is there an uptick in sales since the implementation of your signage network? Furthermore, you can measure the number of items sold per visit. This data is then compared to older data for analysis.
Lastly, and less obvious, is to measure the numbers of clients signing up for loyalty programs and store credit cards. Provided this is something you broadcast over the network. Like sales data, this too can be compared to previous data for dissection.
In conclusion, while there are many ways to measure the impact of new digital signage, sales and visitor numbers are great place to start. Also, comparative analytic tools are almost always necessary for the job.