I have a 10 by 10 in Florida where I store motorcyle junk and business records that I can't fit in my garage. I pay $100 a month, includes 24-hour access no extra charge. Rates at this place haven't increased in several years. I believe this guy is still hanging in there at about 30% vacancy based on my conversations.
In 2005, I rented a 10 by 15 at Uncle Bob's (Boob's). Rent started out at $115 a month. Within two years, it went up to $180, extra charge for 24-hour access. The caretakers sucked, the gate malfunctioned frequently, no one ever answered the 24-hour "hotline" or returned calls and the manager/franchisee was exceptionally rude. After the last rate increase, I told him to stick his business up his nearest orffice. My friends that rented there told me this duffus has lost a load of customers.
Its really no different that any other business, its all about customer service. Charge people a decent, competitive rate. Don't jerk them around with uncessary price increases to line your pocket. For example, property values have tanked 20% here and property taxes have subsequently dropped, so where was his justification for the big increase? Keep a clean and neat facility. Respond to customer issues in timely and professional manner.