To a great extent such shops are being in the right place, at the right time, with enough excellent history with the MSC for them to consider you a 'safe bet' to successfully perform the shop.
As for specific companies, Coyle is probably the company with the most hospitality shops at this point (mostly on the E side of Soflo), though A Closer Look and Service With Style sometimes have things in Soflo as well.
As for the right time, I would not register with these companies until I could claim more than six months to a year or more of doing narrative heavy shops because the kind of shops you are aspiring to are very heavy on narrative. Your ability to write good, clear, narrative without opinions but with detail is critical if you want to persuade them to take you on as a shopper. Giving you an opportunity to do shops for them does not mean they will give you the plums until and unless they don't have a tried and true current shopper who can schedule the shop.
The reality is that most people do not have the writing skills to pull off a very long shop such as a resort. You are likely to be responsible for the equivalent of 50 shops in the 24 hrs you are on location, each with its own checklist and substantial narrative, and all to be submitted very quickly after your departure. There is considerable investment of time by the MSC in getting the visit organized/coordinated as well as in getting your report processed. If for some reason you do not produce acceptable work, they will need to do all that once again for someone else to reshop. And then there is the matter of money. As you know, you will not be paid or reimbursed unless the client accepts the shop. The MSC needs to feel confident that if the client rejects your shop it is not going to pose catastrophic financial hardship on you such that you might take legal action against them or their client despite the Independent Contractor agreements. No MSC wants to reject a shop, especially one with significant financial outlays by the shopper. No MSC wants to continue working with a client who rejects shops the MSC feels were acceptably done. it is a twitchy tightrope and ultimately the reason why they want to work with shoppers with whom they have worked extensively and successfully rather than 'give the new kid a chance'.
Edited to add: Shopper certifications are unlikely to really do anything for you except lighten your pockets.
Edited 1 time(s). Last edit at 03/11/2020 06:46PM by Flash.