I really like Acorns as a micro-investing product, i.e. from the users perspective. While I don't use it personally as it's not suited to my needs, I have reviewed and tested it extensively both professionally and personally for a number of friends and family for whom such a product is useful. Yes, it's not cheap (i.e. you could just buy your own ETFs), but unless you have a good sized lump sum to start with and can keep adding solid deposits each month, you are better off with Acorns due to the lack of brokerage. Doubly as good if you are not financially sophisticated or disengaged with your investing.
However, the biggest challenge from a business owner/investors perspective is that that posed by scale. Ultimately, Australia has a small user base compared to other major developed countries, and the average size of user accounts is generally small. So are they going to get enough revenue to be worthwhile over the longer term? It probably depends on what other activities they get into, like full blown robo advice. Even in the US where numbers are bigger, difficult to pin down if these types of businesses are standalone profitable.
At this point, it's too early to tell, need a good look at the prospectus. I did consider buying in when they did an unlisted raising in 2016 (http://www.instreet.com.au/sites/default/files/Acorns IC_Prospectus.pdf.pdf), but thought I'd hold off until some of these issues were resolved to my satisfaction.
Certainly, one to have a closer look at, and interesting. But a lot of questions that need answering.
