Simply because you can't spend 15 minutes or more on a mattress.
When shopping for a mattress online, you cannot physically test it out before making a purchase. Your only option is to rely on the information provided in the product description, such as the type of mattress, firmness level, and materials used.
However, when shopping in our store, you have the opportunity to lay down on each mattress and take your time making a decision. To ensure you choose the best option, it is recommended that you spend at least 15 minutes lying down in your typical sleeping position for each mattress you are seriously considering.