Yes, you must have a G+ account to upload the photos from. I don't think there is a limit on how many you can upload. You don't have to delete the photos from your account first.Colan as per your recommendation Can I please ask:
1- is this where i says "upload first public photo"?
2- when I click on the above it takes me to signup to google, Can I do that as the business owner or does it have to be a google user?
3- can I upload 10 image using this method?
4- do I have to delete the photos first on my dashboard?