What are possible uses of receiving free SMS from worldwide?
Beyond the nefarious, you could:
1. Have a cheap secondary number for SMS verification. You can
send free SMS from the same number if you link it to a service like
smspup.
2. Legitimately provide it on websites asking for your contact details.
3. Use it for 2FA on various websites, to save your US-prepaid credit.
4. You could setup SMS notifications when your torrent finished downloading
(guide here)5. Use it in a gadget where you send SMS commands.
6. Have an active Australian cell number before you travel down-under.
7. Trick your friends into thinking you moved to Melbourne, Australia.
I'm sure I could think of other reasons, if you want more