I have been doing shops for 5 weeks now and find it great. I have applied to 20 shop companies and have been accepted by 19, but only 3 have enough jobs that can be done in my area, which relates to around 25 - 30 jobs a month. So far I have enjoyed doing this very much.
I am still looking for more Mystery shop companies in Canada to apply to, so if any one has any let me know.