

Well, this abstract says it’s about 20% effective over not advertising but this is a meta analysis and isn’t focused exclusively on internet ads.
The baked in biases being that the authors are “a German chaired professor of marketing at the European University Viadrina in Frankfurt (Oder), Germany” and his research assistant.
Didn’t IHOP do something similar by claiming that they were going to change their name to IHOB?
“IHOb also issued a press release about the change and still used the original “IHOP” in its footer, suggesting the switch was a temporary promotion.”
Seems so. Source.