DD always wanted to suck and suck and was then vomiting all the time (turned out she had reflux). So that I didn't feel like a dummy I actually gave her one the first night we were home from the hospital (not recommended I know). I'd give it to her if she'd been feeding for 40ish mins and not seeming to be taking milk anymore. It helped a lot in our situation and allowed my nipples to have a bit of a break - they were oh so sore in the beginning!