Sounds right to me.
It's a funny kind of obligation, insofar as Wave has delivered the software and received the money. The idea is that theoretically, the client hasn't fully consumed the software until the year is done.
The effect of deferring revenue is to smooth the income in the income statement. Investors tend to find it less nerve-racking when revenues are steady.
I wish the balance sheet clearly split service obligations from cash ones. Same with cash expenses and other sorts in the income statement.