Measuring the impact of communications has long been a challenge (Watson, 2008). While it's easy to tally the hours spent organizing events, crafting leaflets, or composing social media posts, quantifying their true impact is elusive. Similar to assessing environmental metrics through market-based instruments (McKenzie, 2009), evaluating the effectiveness of a communications campaign requires trust, negotiation, and increasingly, reliance on webometric tools and other indicators that communications professionals are struggling to handle. The sentence “In god we trust, all others must bring data” by W. E. Deming is particularly relevant for any head of communications today. They need to deliver data to prove the efficacy of their actions and improve their strategies but, considering an economic market of highly expensive analytics and related services, is the source of that data reliable? And what scope is there for them to trust in their professional judgement?