I agree Jim, that renting use of the station is not an issue. Some of the senarios presented in some posts about the licensing of a "pile of equipment" may however. Consider the following senario:
1) I do not hold an amateur radio license.
2) I set up a station in the U.S. and provide remote access via the Internet.
3) I offer its use for free to any licensed amateur. You tell me your call sign and I give you a password.
4) You operate the station remotely over the Internet using your own call sign. Since I am not licensed I can't designate you as a control operator so I just expect you to become the station licensee during the time you are using it.
5) I won't give you the exact location (street address) of the station.
6) I won't give you a key or other access to the building that houses the station equipment.
Is this legal? I don't think so because you can't accept the responsibilities of the station licensee if you don't have physical access. You have no way of ensuring that the station is operating legally (power output, RFI exposure, etc.).
It would be like putting up a repeater with no trustee and no repeater call sign - everyone just use your own call sign to ID.
Why would anyone pay money to use a remote station that has such shady practices? Why would anyone enter into an agreement to operate a station that has no address?
Obviously, for this to work, there has to be a certain level of compliance with common sense practices. I'm pretty sure the intent of the remote radio provider is to actually become a successful endeavor, not some fly-by-night radio porn site shunned by the ham community in general and probably immediately confiscated by the FCC. With precise business procedures and adherence to the letter of the rules, this could be successful.
As to the pile of equipment, if the owner of such holds no amateur license, and nevers keys the transmitter on-air, then he can't possibly "transfer" control, since control would require a license. The control is assumed by the lessee the first time he keys the transmitter with his callsign on the rented equipment.
If a fellow ham lends you a radio, does he have to first transfer control of the station to you, on-air? What if the fellow ham rents the radio to you? Is he guilty of profiting from your traffic? What if you rent the radio and never key it up? What if you only use it to listen to shortwave stations? It's still a ham radio, and could possibly be used to transmit something somewhere... What then? If? If?
HRO, AES, Gigaparts and all the other ham radio stores don't "transfer control" of the equipment you buy, even if it's used. They sell it. You buy it. Some require a callsign. That doesn't ensure anything. You are responsible for what comes out of the antenna. Likewise, when you enter into the lease agreement with the remote radio site, you would assume responsibility for what comes out of the antenna. When your lease is up, then you are no longer responsible.
NOW... the owner of the equipment will need to be very careful in accepting users, since a violation could result in confiscatory action.
I'm sure these entrepreneurs have taken this into consideration, and the lease agreement will be more than an internet credit card transaction and boom, you're on the air.
As I see it, the rules are built on prescribed practice, not hypothetical opportunities to break rules. The pile of equipment analogy is simply for example. The reality is these remote radio sites are more than likely owned by licensed hams who will indeed be able to transfer and accept control, and they may well also periodically check in on things to see if everything is running well. I would, if it were my business.
That's just my interpretation. In my opinion, this could work and is legal.