Month to Month after a year lease...why?

[Chuy Gonzalez]

I was discussing with my PM company about writing new leases for two great tenants this year. The PM company told me they usually go month to month after a year's lease. She said it was easier to raise rents that way. I thought back to the days when I rented, and I remembered that most of my places went month to month after a year. Why is this practice so prevalent?

These two tenants are solid gold, responsible, quiet, pay on time, good job, no drama tenants that I really, really want to keep