I like reading mobile marketing case studies (I think it's a side effect from all the EDGE radiation I have absorbed), and Bluetooth marketing for mobiles looks pretty difficult. Plus given what I have seen it provides little benefit over barcodes in some situations. If I have to get close enough to read instructions I could have scanned a barcode instead. Even someone unfamiliar with barcodes would probably have an easier time installing an application than configuring their Bluetooth.
Since many people are still a little unsure about Bluetooth marketing, voluntary opt-in is difficult to trigger gracefully. This is less difficult with other calls-to-action like SMS/Email, barcodes and RFID where interaction requires deliberate action, but the required action is so simple that a transaction can be completed before the impulse to participate subsides.
- SMS keywords and "empty mail" (Japan's mobile email equivalent to SMS opt-in) require the user to transmit information from some media to their device. Somewhat inconvenient, but it definitely constitutes a voluntary opt-in.
- 2D-barcodes require the user to activate their code reader and aim their device's camera at the barcode. The device them reads the information from the media itself. Since the user does very little to facilitate the transfer of information, it would take the same amount of time to input a page of text as it does a URL. It can also be used to trigger the other forms of opt-in such as SMS, empty-mail, web access, client application download, or even further instructions or special information about a campaign. It could contain all of these at once. Granted, these are best suited for print media. People can remember an short code/keyword long after the commercial is over or the magazine is lost, but barcodes demand immediate participation unless they can take it with them (say, on a business card). Still I think the act of scanning a code is engaging rather than tedious (like typing an SMS). You can even embed extra information like what publication the ad is running in or what region the magazine was shipped to, etc. Planned well you could gather some interesting demographics this way.
- With RFID the user must get their device deliberately close to an antenna. It is possible the use could trigger their chip accidentally, but I haven't seen this happen. RFID is a very nice blend of requiring deliberate participation while keeping the transfer mechanism super simple. "Come a little closer." The problem is that not so many devices are equipped with chips.
Then again this is my relatively uninformed opinion. - Bluetooth is a little different from the others. Most of the time you are prompted to participate without initiating contact (walking or even riding your bike by a shop does not count as an opt-in). Other times you have to follow some instructions to make your device receptive to the campaign. Since many people are concerned about nasty-ware and Bluetooth security this may considered invasive and bothersome. Most of the time the mechanism is bigger than the message. All that work to get this image on my phone telling me to buy your product. If it had been an old-school print ad you might have found my way there in the time it took to get the message via Bluetooth.
"Biased"? I don't know what your talking about. Denso Banzai!
Since most phones have cameras and scanning applications are free and many, there is more of a hardware barrier to RFID than barcodes. Plus it is generally cheaper to place a print ad than a networked RFID station.
There is nothing wrong with SMS/Email opt-in, and as I mentioned barcodes can be used to facilitate these mechanisms in situations where it cannot replace them. For instance, you can scan a code and be presented with an SMS, recipient and message already filled in and ready to send. The same can be done with email. URL's, contact information, encrypted data (like on Japanese work visas), double-byte characters, control characters, and so on. Lots of possibilities, and I have a feeling that this will blow up in 2008 in Europe and the US. At least I hope so ;).