I see Insta-Shops on the map, but they're all marked as "Reserved"

Gray "reserved" pins are used when Insta-Shops aren't available, but might be in the future, if a shopper fails to complete an Insta-shop that they've claimed.  This happens in two situations:

• When the Insta-Shop has been claimed by another shopper.  If the shopper fails to complete the shop in time, the pin turns blue and the Insta-Shop becomes available for you to claim.
• When shoppers have claimed all the Insta-Shops allowed in the shop quota.  In this case, you may see a lot of gray pins -- and you may even see the pins suddenly turn from blue to gray.  This happen, for example, when a client provides 50 locations, and asks for 10 Insta-Shops to be done at those locations.  When the tenth Insta-Shop is claimed, ALL the remaining pins turn gray.  If any of the claimed (but not submitted) Insta-Shops are not completed in time, the pins will turn blue again, and the Insta-Shops will be available again (note: this can also happen if a submitted shop is rejected).