It's a bit curious that Back Channels is in a faction which has exactly two advancable assets (Contract Killer and GRNDL Refinery) which don't even work well with Back Channels. Though I guess I see why it's in , the mechanic of trashing your own cards for money is a Weyland thing (Liquidation, Reuse, Security Subcontract).
Back Channels ultimately functions best as a hedge against failed traps. Normally a failed trap stays on the board until you replace it, usually because you need the server. With Back Channels you at least get some money back.
An obvious combo is to use the easily splashable Back Channels (1 influence) in Jinteki with Mushin No Shin and a Project Junebug. Generally speaking a runner will be very wary of a Junebug at 3 since it deals 6 damage. So the runner may just be inclined to leave that card hoping it's a trap and not a Ronin. Normally a strong indication of Ronin is a fourth advancement token. When the runner knows you have Back Channels that indication is less strong however. A Mushin plus an extra advancement token makes Back Channels give you 12. That's a viable strategy. A Junebug at 4 is a whopping 8 net damage, also a viable strategy. And a Ronin is a viable strategy.
Since there are now three obvious strategies you could use, two of which would be bad for the runner to leave on the table the runner may be inclined to draw up to 8 and run. For a true Ronin that's the worst case scenario. For a Junebug at 4 it's not a bad scenario, sure you lose the potential of 12 but the runner would lose a lot of tempo in springing that trap.
Jinteki is about strategic ambiguity, about having cards on the table that could have multiple roles. Back Channels adds meaning, which is a very good thing.
NBN also has a bunch of advancable assets. A neat combo is to use Ghost Branch, slowly advanced by Early Premiere. It costs you 1 per turn but you can eventually cash it for 3 times the amount you've put on it. If you do this in NBN: Controlling the Message interfering with that plan would be expensive for the runner, 2 and a trace 4 for a tag if trashing the Early Premiere, a bunch of tags if trashing the Ghost Branch. Plan B is also worth considering.
In HB there are of course a bunch of traps. But there's also Thomas Haas. Now normally Mr. Haas doesn't work very well as an economy option since you pay 1 + 1 to advance and each advancement token is worth 2 which is by usual Netrunner standards worth less than a credit and a click. With Back Channels he becomes worth more and you still have the option of dumping him if the runner goes for him. That said, I think I prefer a Cerebral Overwriter.
All in all a quite good card, mainly for trap decks where a hedge against failing traps is welcome.