Google Calendar has recently introduced appointment slots attempting to compete with its many partners that provide appointment scheduling functionality that is integrated with Google Calendar.
We are really not sure if this functionality is the result of Google thinking strategically and making a decision that it wants to compete in appointment scheduling or it is just a group of engineers that decided to venture into the space without any directive from management.
Regardless of the reason, the community at large is fortunate that Google requires that your other party opens a Google Calendar account before it can schedule with your appointment slots. This limitation is a major one and we are happy about it as no business can afford to put hurdles in front of their customers and ask them to sign up for a Google Account in order to schedule an appointments. This limitation makes the Google appointment slots appropriate only within organizations that already work with Google Calendar. Lets hope that Google keeps it this way.
So if you need a real appointment scheduler that works like Google calendar appointment slots without Google account check out ScheduleOnce. Its is tightly integrated into Google Calendar and is extremely wasy to use.