Update: Now that I've had the pack for 4 months with almost daily use, I have a few comments to add. First, I still the backpack for its simplicity and lightweight. I sometimes stuff the bag into its little pocket, and stuff the whole thing in my bike jersey pocket until I get to the store to make my purchases. Or I put 5 heavy library books in the backpack to return books, and then stuff the empty backpack in my pocket to ride home. It's just so convenient. Keep in mind that none of this is more than 20 km away. Second, on the issue of washing this--I have washed it 3 times now. It was getting dirty from my daily use, once it got some bike chain grease on it, and once it had a huge patch of oil stain from the take-out food I was carrying. I treat the fabric with stain remover, and put the backpack in a laundry net (for delicate fabrics), and throw it in the washing machine with all my other clothes on gentle cycle. Then I hang it to dry. It looks as good as new. Whether the laundry net is necessary, I'm not sure. I just didn't want the straps to get chewed up in my washing machine.
Initial review: To those considering this product, I think you need to first know what you are using this pack for. This is not the heavy-duty kind of pack you take on a multi-day hike through the bushes. This is not the kind of pack that has a structure to it to stay in shape without fully stuffing it. There is no waist or chest strap to keep the pack from falling off your shoulders if you wiggle too much.
Now that's out of the way, you can consider what this pack is good for. It's great for packing on a trip in case you needed a back-pack, as it is ultra lightweight and compact. It's also awesome for a quick grocery run around the block. I bought this to hold my work clothes/shoes so I can stuff the bag into my bike pannier. If a pack as too much structure or too much padding in the straps, it won't fit in my bike pannier. This bag is perfect for the short distance I walk between the bike locker, the shower room, and my office, while holding my clothes/shoes. I don't want to take my bike pannier off my bike everyday while it's wet/muddy from my ride. This bag's thin material and lightweight nature is just perfect for my needs.
So, while people criticize the product for what it's NOT, please consider your needs before you buy it.