Well, "WBU" stands for "What about you?" It is a friendly way to solicit someone's opinion or experience, usually found at the end of a message. For instance, if a friend says,"I like movies! WBU?" he/she/they mean, "I like movies! What about you?" This is an informal term found in the dialogue of friends and family for easy sharing of thoughts and continuation of the dialogue. So you can say that meaning will be same both platform social media and text.

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