Salty snacks like peanuts and pretzels can often be found for free at gatherings where beverages are for sale. vendors hope that the salty snacks will make consumers thirsty so they will purchase something to drink. why does this work?

This works as the salt in the body generates a hypertonic solution surrounding the cells that makes the water to move out of the cells and make them crenate. A hypertonic solution refers to a solution with more molecules of salt (solute) in comparison to the molecules of water (solvent).  

When the salt in the body develops a hypertonic solution surrounding the cells, the water moves out of the cell osmotically, that is, from high concentration region to low concentration region. The loss of water by the cells makes them turn crenated.