For me it's already accidentally backfired for them because it's meant that I've just learnt I'm not a member, and backfired in that the reaction has been 94.76% (according to the poll) negative so far.
I'm another STH who naively assumed that my multiple hundreds of £s a year to the club meant I automatically was already a member. Don't buy tickets for mates that often as most are able to sort themselves tickets so not that fussed about this option anyway.
This has backfired spectacularly.