DD1 I waited for 6 weeks before trying the dummy as I was worried about nipple confusion, she fed constantly at night. As soon as dummy appeared she fed once! It was a lifesaver for me. Fast forward 2 years and DD1 still has dummy, or dummies, hidden around the house. Would have it night and day and I now have to confiscate them as she has went from saying Granny to Gwanny 
She will be giving them to santa, [hopeful emoticon]
DD2, i didn't wait til 6 weeks, lasted 3 weeks and she only takes it for daytime naps and she drops it after sleeping for a couple of minutes.
She'll be 9 months at christmas so the plan is that Santa will get them too. [doubly hopeful emoticon]