TripAdvisor, Wayfair and pet-food maker Nutrish on Thursday became the first major brands to say they will stop advertising on Laura Ingraham’s Fox News program in response to the host’s mockery of a school shooting survivor from Parkland, Fla.

The targeted student, David Hogg, is trying to pressure other companies to abandon Ingraham, too, but history shows that advertiser boycotts of highly-rated Fox News shows are difficult to pull off.

“David Hogg Rejected By Four Colleges To Which He Applied and whines about it. (Dinged by UCLA with a 4.1 GPA…totally predictable given acceptance rates.) https://t.co/wflA4hWHXY”

— Laura Ingraham (@IngrahamAngle) March 28, 2018