Why is trademarking words a good idea?

Lately #taylorswift trademarked specific phrases like "Nice to see you.® Where you been?®" to individual words like "fearless®."

Where is she going with these trademarks? Is this a good idea?

Can you trademark a book title for example Chicken Soup For The Soul? Click the link to find out...

#trademark #copyright #businessmodel #booktitles #branding

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