Originally Posted by
bunyip
Easy peasey, lemon squeezy.
Tricks of the Santa trade, number 1. The EICOA* always takes a note of each child's name, age and some sort of 'secret' information (eg. favourite colour, pet's name, anything) then relays that to Santa whilst the children are traversing the 'winter wonderland'. Forewarned, Santa then surprises them by knowing all this stuff.
It all sounds really magical, but it's actually very educational, in that it prepares them for the later realisation that the UK government is doing this all the time by CCTV, illegal 'phone taps, email scans, undercover police of the Mark Kennedy type, etc. :p
*EICOA = Elf in charge of admissions.