OK.. First off - you are not reading or simply not understanding what I wrote and you are missing the original point of the OP. Yes, of course the app has to handle "the rest" and all that jazz. You can disagree with my sentiment about the importance of the OS all you want. The point about "registering listeners" is completely moot. And the premise of efficiently downloading music is completely irrelevant. What I simply try to convey is the transferring a song as an example of a non-complex single file binary that proves the failure of the premise of A beam. It does not get any simpler than that. It gets complex with album art and other metadata but that's not what I am trying to convey.
You have to understand the audience of dozens of millions of Android 4.2 users. They don't know what we know. They know what they see in the store and what they see on the Lumia commercials ("The one trick pony gimmick"). A beam could have value as an ad-hoc sharing solution (irrespective of speed, efficiency, etc.) if it was created and marketed accurately. It's a simple and provable fact that you can do to see where the failure occurs. Here are the instructions:
1) Turn your Geek Brain off and make believe you are <put your favorite non-geek personality here> (I'll use my example - my wife is a doctor)
2) Follow the instructions of beaming from a Samsung Galaxy S3 to an Nexus 7. This means turn on NFC on your Samsung and turn on A Beam on your N7
3) Open up an app like Google Play Music on both devices and find a song on the S3 (your source).
4) Put devices back-to-back
5) Feel the haptic feedback that the OS (yes, the OS and hardware, not the application) says that "NFC is working"
6) See the S3 screen shrink to A beam size and report the instructions "Tap to beam..."
7) Tap the the S3 screen and see the feedback (coming from the OS, not the app)
8) Then watch while the file transfers to the N7 from the S3.... or not.....
So, my wife, the doctor, recognizes that everything is working just fine... Just like 10s of millions of other users she has received all the indications that everything should work. But in reality, nothing is working and therefore, like the OP, a forum question is asked or a call is made to Verizon or Google or ATT or USCC or SPRINT or.......
So simply put... forgetting about registered listeners, and IP stacks, and all the techno-jargon we can muster.... The simple point is that "A-beam" does not work unless you know what it works with. And when apps indicate that they are NFC compliant and Samsung creates "S beam".... it means absolutely nothing to 10s of millions of users. (and by the way, S beam does not work with A beam compliant apps all the time... how about that disaster. So you have to turn on A beam instead of S beam but there is no longer an A beam option on the S3, it's now simply called NFC...). The world of networking is my world (for almost 30 years now) and the likes of Google make it more confusing than it really needs to be by changing names, variants across platforms (ala Picasa), and a lack of interoperability between OS supported devices and applications on those devices (S3 and N7 as an example).
As far as music management goes, will not use Google Music Manager because they have a very well documented track record of application abandonment. Thank goodness for Drag and Drop. It has worked since the early days of Macintosh and Windows 2.0 and is still relevant today.
AGE