Lots of people have said that they would like more variety within yoto club, so why not rotate a few cards, or card packs, that are a part of the regular yoto card store, in and out of yoto club once a month?
That way people would most likely keep their yoto club membership because they will be looking forward to new cards each month. It would be exciting if a card that someone has been wanting, shows up as a yoto club option; then the next month some of those cards would leave yoto club and just be a part of the regular yoto card store.