This has varied with each child. For the most part by two years old my children were done with the pacifier. My youngest has sensory deprivation and at 10 it's become a struggle as he is a finger sucker...mostly at night.

I pretty much left it to them & it worked itself out.

Out of 5 kids I only had one that took it and at 13 months he got sick and when he sucked on the pacifier he screamed I think it hurt his ears and he gave it up cold turkey. He would not even look at it. It was so strange.

My son wasn't too big on the binky...if I remember correctly, potty training was tougher until he decided he was ready..lol. 

I was scared to give my first born a pacifier because I was trying to establish breast feeding and it was really hard!  He never really used one.  Then my daughter was born and the sucking reflex was very strong.  The first night I had her home she nursed for hours straight and I ripped the house apart trying to find a pacifier so I could get some sleep!  She outgrew that around 4 or 5 months probably.  My third use hers in her crib only until she was almost 2 which was far long than I had intended! 

Yeah, I think it's a good idea to allow the child to decide sometimes.