Pompeii tickets for kids

[peasprout]

I found out that Pompeii tickets are free for kids under 18, but you can't purchase them in advance.  You have to go to the ticket counter.  How horrible is the line (meaning is it worth the free ticket)?  It seems I can purchase in advance through an unofficial site, but I'd have to take the voucher to the "booked" desk of the ticket office.  Is that line better?  Anyone have first hand experience?  Thanks!

[euro cruiser]

The charter of the site (Pompei) says that no one will wait more than 15 minutes in line.  I've been there a half dozen times over the years and have never waited more than a few minutes, so my experience bears this out, but that's not statistically significant.

 

The only time I know when there are guaranteed to be pile ups at the entrance are on the free days, the first Sunday of each month.  I would avoid that like the plague, the crowds are not worth saving 22 euro.