Approaching its first anniversary, Mayor David Smith said he was generally happy with how Sunday shopping had been accepted by business and shoppers.

"I suppose the only disappointment was that initially there appeared to be solidarity with CBD traders especially the small ones," he said.

"But as the year has gone on some have broken ranks."

Bunbury Chamber of Commerce and Indu-stries chief executive Allan Birrell said the first 10 months had gone as it had predicted.

Mr Birrell said there was not yet a viable return for owners on the cost of opening an extra day.

"(Retailers) make their own decision based on their perception of the market and demand and the demand on Sundays is not there," he said.

"Extended trading will only be effective or worthwhile to smaller retailers when the numbers of visitors increase."

Mayor Smith said the Perth to Bunbury Highway was already bringing more visitors and the number of shoppers is expected to only increase.

He said Sunday had also become the best day to shop for people who preferred easier parking and a quieter experience at centres.