Through Jobslingerplus I signed up to all sassie platforms. I've also signed up to maybe 2/3 of the companies listed on MSPA website. The one thing I noticed is that eventually I stop receiving emails and have to reactivate my email because gmail blocks it.
I definitely understand the notion of newbies focusing on getting experience and building a rapport with schedulers. I've been mystery shopping for about 18 months. The amount of shops I work vary monthly since my aim is to earn $500-1000.
However, I'm now looking to branch into new MS assignments and learn about other types like possible apartment shopping (I receive notifications for those).
Shops I've worked included: opening acct, bank inquiry, gym inquiry, medical related, retail product shopping/experience, food/restaurant related, ordering cable, phone shops, testing centers, testing an app (first one and best one), tourist related activities (love them).
Shops I would like to perform: casino, household related (carpet cleaning etc), reimbursement shops related to products rather than just food (love freebies).