Girlguiding does a regular large scale attitude survey open to all, why is this one only for randomly selected random people?
I thought they meant don't share the survey contents online, which sounded dodgy, but what they actually mean is don't share the link, as it can skew the results if other uninvited people answer it.
Random selection of participants (e.g. putting all the people in alphabetical order and selecting every 10th person) is a legitimate way to run a survey from a statistical perspective, and it's a good way to get a cross section of members without having to survey everyone (which often costs more).
If they want to get a steer on people's current thinking and on whether they're going in the right direction or are risking fucking up royally, a random selection would be a much quicker and cheaper way of doing that than surveying every member.
Also, it's worth remembering that the people who come onto this board to say they've received it are far more likely to be consciously GC than the general population, so several GC people on MN saying they've received it doesn't mean it only went out to GC people.