"It's a classic David and Goliath, or Bob and Goliath [dispute] and everyone knows where consumers' hearts and minds will go - they will go to Bob," Bickford said.
He said the dispute came at a particularly bad time for Sanitarium, which has been forced to stop making Marmite due to earthquake damage at its Christchurch factory. Stocks of the popular yeast spread have run dry across the country.
"In brand management terms I would be saying, 'Let's just leave Bob for the time being and get on with getting our house in order'," Bickford said.
"It's never a good thing for a big corporate to be publicly taking on a little guy."
Wren has accused the food manufacturer of "corporate bullying", but van Heerden said last night that Sanitarium liked to "resolve these matters amicably with the people involved".
He said the company had approached big retailers in the past over trademark issues.
"So it is not about big or small, it is about treating all breaches of our trademark in the same way," he said. "One can't treat the stores differently, as that creates a precedent."
Sanitarium, which is wholly owned by New Zealand's Seventh Day Adventist Church, forced Onehunga's English Corner Shop to stop selling Weetabix in 2010.