Complex sentence: These were followed by specialist "sales-only" retail outlet chains (where alcohol is not served on the premises), and these now account for most of the alcohol sold in Australia.
Split into simpler sentences: These were followed by specialist "sales-only" retail outlet chains where alcohol is not served on the premises. It is still unusual for alcohol to be sold in retail grocery stores in Australia, and specialist liquor stores account for most of the alcohol sold in Australia.