It's a clever use of personalisation, re-targetting and good-old fashioned pester power.
After students have created a wishlist, a custom URL link is sent to their parents in a personalised email. Once the parents click on the link they are 'cookied' which enables the site to retarget them with online banners, with different messaging based on the profile their child has picked out for them (like penny pincher or helicopter parent).
Take a look here: http://www.newegg.com/back-to-school-shopping/
A Quick Snapshot of How it Works
They start by creating a wishlist of the goods they want.
Next they select which type of parents they have (penny pincher, helicopter parent, workaholic, BBF or geek..) This information is used to customise messaging in emails, banner ads and videos.
Then they give their parents names and email and their own name and email and approve email, banner ads and posters to be sent to their parents.
Banner ad example:
thanks, em