In 2020, Share of Search was confirmed as a leading indicator of Share of Market — when Share of Search goes up, Share of Market tends to go up. The gap between them, Extra Share of Search (ESOS), is a particularly solid indicator of market share movements.
Share of Search was a new measure for brand strength and health, measuring the base level of Share of Search without advertising.
Now we are starting to look at Share of AI Voice — or Share of AI — if we take a similar view on AI replacing search, and beyond, becoming the interface for the internet.
The difference now is we are really early. In 2020, search was very mature, so it made sense to compare search visibility as a share-of-voice indicator, and we could directly correlate share-of-voice increases when successful campaigns broke or new product trends emerged.
Just picking a category — restaurants — we can see how much of a deficit there is in performance relative to market size. The other reason this point in time is interesting from a measurement perspective: AI values a coherent brand, and compared to share of voice in search, the loudest brands are NOT the most successful brands when it comes to AI visibility.
I am measuring this and 12 other sectors each week to understand how brand performance and commercial performance correlate in an AI-native world. Only 20% of consumers use AI to find restaurant information in 2026, so we have a long way to go until we can connect commercial metrics to AI visibility.
What we do know: brand strength = shareholder value. In an AI-mediated world, brand strength will equate to more than visibility.