I joined up to YouGov a few weeks ago. If you remember they are an online polling organisation that conduct market research for whoever pays them.
YouGov gather demographic and other info about volunteers who sign up e.g. age, house ownership, postcode.
The idea of such research is either: they poll a particular group (e.g. home owners) or a "representative sample" (equal numbers of men and women) or a sample that represents the population.
Concerned about whether YouGov members as a group are representative of the population (you need to sign up, you need to have a computer etc).
I am also bemused by some of the question design. I had one last night about memory. One of the questions was about "which of these numbers do you always remember" (or was it never forget... anyway) . List included NI number, emergency services number, and a list of phone numbers. Including "dad's" " mum's" and "best friend". Smacked of a question designed, badly, by a first year university student. I pointed out in the comments that as "my dad" died nearly 60 years ago, he never had a phone number. 
Any other members members of YouGov - and how convinced are you by their output?
Elderly fellow gran has become loudly racist
Angela Rayner lashes out and calls Sunak “pint sized loser”.
Recommendations please, for a stopover on the way to Loch Tay
