IS Pacifier GoOD OR BaD?

OKAY MY NIECE IS 3 AND WILL NOT LET GO OF HER PACIFIER..BUT I WAS READING..SOME SAY TAKE IT AWAY, ITS BAD..BUT THEN SOME SAY YOU SHOULD JUST LET HER KEEP IT AND WAIT TILL SHE GETS TIRED OF IT..WHAT SHOULD I DO??..BECAUSE I TAKE CARE OF HER YOU KNOW!