Title: Make sure not to drop it.
Review: After about a week of using the mug, during which that time it worked fine for my needs, I dropped it on a concrete floor and ever since then it has been leaking from the bottom. It seems that it may just be the condensation (I was using it primarily for water) that accumulates between the two layers leaking from the joint on the bottom. I regret being clumsy enough to drop it in the first place, but I also expect products such as this to be a little more durable than becoming useless after a four foot fall.
Is this product review negative?