This would be mainly useful for those eligible for Government co-contributions, a nice double dip.
Otherwise OK if you can easily divert your super, the $100 should be protected from fees and possibly cashed out at income tax rates later if you want.
You may also be able to take home a free Year of the Horse money box :-)
$50 is tiny comparing to the potential fees charged by the superfund managers. However having a look at Smart Choice Super the fee is actually not bad — $50/year admin fee + 0.5% investment fee on any option (except cash that's 0%).