The names 'Tupperware', 'Lorraine Lea Linen', and 'Chefs Toolbox' often remind people (especially women) of an evening with friends buying high quality products which are more expensive than what you would get in stores, but are also of much higher quality. These types of direct selling companies offer commissions to their sales force in return for them actively selling the products.
In the last 12 months here in the office, we have had two staff members who have taken up these opportunities so there has been some discussion about when it is no longer classed as a hobby but is a business and so the income needs to be declared. Income in this example is the commission that is earned off sales, not the total sales amount.
There is a list of questions on the ATO website which help to determine whether the activity you are undertaking is a business or a hobby. They are questions regarding the goal of the activity, manner in which it is undertaken and the characteristics of the activity.