He's a natural!

When I was around 7 or so, I remember my parents taking my sister's pacifier away.  Since I was a responsible big sister, I showed her how her thumb could replace her paci.  This habit stayed with her well into her teen years.  Well, no one is going to have to show Holden that his paci can be replaced.  He spits his out in favor of this new and fun activity:

It kept him happily occupied for at least 30 minutes the other day.  We struggle with the decision to encourage the paci over his thumb.  Which is worse?  Which habit is harder to break?  Even if he becomes paci dependent now, will he just replace it with his thumb when we take the paci away?  Deep questions!