Retailers are expecting another busy day of trading in Adelaide, on the second day of the post-Christmas sales.

Yesterday an estimated $250 million was spent across SA, with tills in Rundle Mall alone accounting for $100 million of sales.

Theo Maras from the Rundle Mall Management Authority says public holiday trading is bigger than just retail spending.

"There were people who were happy to just be there," said Mr Maras.

"There were people happy to see Adelaide alive and burning. That's what it's about; it's not about  [running] in to shop and spend your hundreds."

Sales are up almost 14 per cent since last year and are expected to top $1 billion in SA alone.

Photo: Getty Images.