There are many reasons to use a travel bottle, including: -TSA size rules for liquids. Travel bottles ensure that you stay within those limitations.-Travel bottles save room. Even if you're checking a bag and don't need to worry about TSA size rules, travel size bottles ensure you don't pack more than you need-- and have plenty of room left for souvenirs! -Good travel bottles won't leak. While you normal shampoo bottle probably isn't designed to be leak-proof, good travel bottles are! All it takes is one leaky bottle to ruin your clothing, so we think travel bottles are a great investment.