Author here. The key differentiator is the use of cable, which was at least 15 years ahead of its time. While the service itself was capable of bidirectional communication like a modem, it was often on one-way networks because the technology had not been upgraded.
Quantum Link and Prodigy are likely the most common comparison points, though this used a proprietary platform for much of its life, leaving out people who already owned, say, an IBM PC or C64.
Probably comparable to Quantum Link: an online service that served a homogeneous network of home computers through custom client software that allowed for running arbitrary executable code.
