I am someone who has a lot of back pain so I was looking for a nice firm bed so that I would not wake up in the morning stiff and in pain. After taking it out of the package I let it expand for about 36 hours before I slept on it. I wasn't sure how long to leave it for and when I looked in the product description I couldn't find any information which was a little frustrating. In the reviews some people said they left it for 24-48 hours so I just went in the middle. The bed is a lot softer that I was expecting for a "firm" bed so I was worried that after sleeping on it I would wake up with back pain. However I was pleasantly surprised that it was not the case. The bed is very comfortable and offers good support. It definitely sinks in on the sides a little but it is not a big deal to me. For the price this is a good deal.