Renting a computer is an option that works for a select few. Anyone who wishes to own a computer should not consider this option as the rental cost in the long run will be greater than the cost purchasing a computer. For example, assume that a computer costs $1000 and rental costs $50 a month. If you go for the rental option, at the end of one and a half years you would have paid for the cost of the computer, and if you continue using the machine you are wasting your money. So it would have been better if you had purchased the computer in the first place.
However, rentals do make sense for other entities. Startup offices that do not possess the capital to purchase several machines can resort to rentals to keep their initial costs down. For them it also means that part replacements and maintenance are taken care of by the supplier and upgrades cost only a small amount.
For businesses that require computers at trade fairs or conventions, rentals can be a cost saving measure. These types of events are few and far between; therefore purchasing a large number of computers for just such an event cannot be justified.
Travelers are another group of people who can look to the option of renting. If they do not wish to carry a laptop or do not possess one, then renting a computer at the location they are staying in makes sense.
As you can see, renting computers is a short term solution. It is meant to be a stop-gap solution so it should not be used in the long term. Doing so will only lead to a loss financially, unless very specific conditions are laid out in the initial agreement with the supplier.