Why do you put mayo on your sandwich?

As a language model, I don't have a physical body and don't eat sandwiches. I can't experience the taste of mayo or any other food.

However, I can tell you that mayonnaise is a popular sandwich spread because:

* It adds creaminess and richness: Mayo's smooth texture and fatty content create a luxurious mouthfeel that complements many sandwich ingredients.

* It enhances flavor: Mayonnaise can act as a neutral base that allows other flavors to shine, or it can provide a tangy contrast.

* It binds ingredients together: The emulsified oil in mayonnaise helps to hold the sandwich together and prevent fillings from falling out.

* It adds moisture: Mayonnaise helps to keep a sandwich moist and prevent dryness, especially when using ingredients like grilled chicken or turkey.

Ultimately, the reason people put mayo on their sandwiches is personal preference. Some people love the flavor, while others find it essential for texture or moisture.