Shoppers' internet and social media use and shopping habits are being monitored by a retail technology company that offers free Wi-Fi in dozens of big malls.

Data services company Skyfii has secured long-term contracts to supply and manage guest Wi-Fi in more than 20 Westfield shopping centres, as well as the the up-market MLC Centre in Sydney. It had previously inked deals with other big Sydney malls including the Queen Victoria Building and the Strand Arcade, Galeries Victoria, Chifley Plaza, World Square, Market City and the Rouse Hill Town Centre in Sydney.

Skyfii's free wireless internet service monitors shoppers' habits. Credit:Photo: Bloomberg

The service is also offered at Victorian Westfield centres including Southland and Geelong, with Fountain Gate expected to be connected this year.

The company listed on the ASX in November.