I looked at doing this, but haven't yet. I am confused about the price though. The OP said $29.99, but this site says $18.00 and reviews each months deliveries.
August Barkbox Review | Ramblings of a Suburban Mom
If it's $18, it might be worth it. For $30, IMO, no. I'd rather choose my treats and donate directly to my local shelter. I would be annoyed I was told I was getting a certain thing or number of things and instead something else or a lesser quantity came.