What is the most representative way to measure the impact of a digital signage deployment?”
This is a difficult question for a single unified answer unless it’s generalized in a way that applies to all environments. In my opinion, the impact might be very different depending on the goals for the deployment and possibly the environment in which it is implemented.
If the goal for the deployment was to increase advertising revenue by 100 percent, then total ad revenue generated would serve as the measurement. If the deployment served to increase sales of a product or service, then obviously, total sales revenue would serve a similar purpose. The impact could also be a subjective measure of customer loyalty or strengthening of a brand and might have to be determined via surveys. A multi-faceted approach might require looking at all three measurements listed above and/or other criteria as well.
A deployment might also look at cost savings instead of increased revenue. Increased safety or security might also provide a measurable metric. Providing real-time information in situations that benefit a customer or improve logistics over static paper-based materials might show up in productivity or reduced transactions times thus contributing to the bottom line indirectly.
Although a little creativity might be required to actually measure the impact of a digital signage deployment, providing a goal for the deployment coupled with an understanding of the current baseline without the deployment should allow for meaningful impact measurement and provide the opportunity to assess cost effectiveness for future deployments.