I understand there will be some doubts from parents when I started such schedule 3 years ago. Let me provide some explanation here.
First, 6 or 8 weeks are not enough for most workbooks. Most Steps have more than 10 lessons for the core and for the plus. Changing length for each course will make the classes more confusing and more difficult to manage.
Second, I offered two ways to pay the tuition, pay twice or pay once. Of course I will give some discount if you pay once. If you change mind, or your child lose interest, or your child's schedule gets changed, you can always stop in the middle, after 17 lessons. I am not forcing you do the whole year.
Third, I promote persistence through teaching chess. If you want to achieve something, you need persistence. Signing up one-year class is one way to learn persistence. People are too easy to give up something when they meet some difficulties. When you learn chess, you will definitely hit upon some bottleneck. Providing an easy way to get out is not our goal. Sometimes it's just a small nudging, persisting one more week, or trying one more time, that makes difference. Nobody complains about schooling, and most of us graduate from schools with no problem. What we are doing is just a chess school.
Fourth, with longer commitment, I have no need to worry about student source all the time. I can devote more time to help parents and students, and less time to advertise for my classes. I only advertise my steps class once a year, in summer. I don't advertise them in other 10 months.
Fifth, with stable student pool, it's much easier for me to know all students, and track their progress, so I can provide the best help. I can plan longer, without worrying about churning and re-aligning student level in the class.
Sixth, with fixed schedule, it's much easier for me know which area needs enhanced, which parts can go quickly, what contents should be added, etc. So I can improve my classes year over year.
Luckily, my last 3 years were quite smooth. I teach about 30-50 students a year. We started yearly schedule in 2019. In 2019, only 2 students chose to quit in the middle, one had schedule conflict, and another reason unknown. In 2020, 12 students chose to sign up next steps, and only 4 students chose to quit in January, 2 with conflict schedule, 1 went back to China, and I forgot the reason for the last one. This year, we have 13 students chose to continue with Step 4 and Step 5, and some stay with me for the third year. Right after pandemic, we saw couple students have seen their rating jumped for hundred points, up to unbelievable 785 points (710=>1495).