Bluetooth marketing is the use of Bluetooth technology as a method of communication. Bluetooth works in a similar way to the wireless networking technology most people have in their homes. Like wireless networking it passes through the air creating a connection between two devices. Wireless technologies of all kinds can be interrupted by obstacles though with careful planning Bluetooth transmitters can be positioned to minimise interference.
Bluetooth marketing uses Bluetooth technology to communicate with mobile phones that have Bluetooth enabled. The marketing element relates to the message you send.
If you are advertising something you will use Bluetooth for marketing purposes, though charities could use the service to promote a specific campaign to create awareness. Bluetooth is certainly not only for advertising!
All of these terms refer to the same technology; Bluetooth marketing, Bluetooth advertising, proximity marketing. When the term proximity marketing is used, the relevance of Proximity should not be lost.
The range of the Bluetooth transmitter you are using affects the type of message you should send and how you support that message within your campaign.