There is no major online marketplace operating in Australia that sets a commendable standard for respecting consumers’ data privacy. Letting customers opt out of data tracking would be a good start.
An entire industry exists to trade on your personal data - everything from your shopping habits to your political views and medical conditions. The results can genuinely harm consumers.
The Australian Competition and Consumer Commission says the sheer dominance of Google and Facebook has distorted other businesses' ability to compete on their own merits.