So I have a free license and a board that a team of 10 people work with and 20 others should only read. Costs me nothing. In order to use the Observer restriction on the 20 I need a business class license. $10.00 a month per user times 30 users equals $3600 a year, just for observer licenses. Who would be foolish enough to pay that when they can make do and pay nothing.
Now if you required business class but didn’t count Observers in the user count, it would only cost me $1200 per year. Better but still too expensive. We’re talking one or two boards. Can’t justify value against cost.
May I suggest a Professional class, permits Observers but doesn’t count them. $4 or $5 a month. For my use case that’s around $500 per year. Then I might buy it.