The article misses one point in it's analogy to paying for promotion: who's being paid. When I pay a store for special placement, I'm paying the store for special placement of my stuff on it's shelves. That's fine, it's the store's shelves and they're free to handle them however they choose. But suppose that, instead of placement on the store's shelves, I'm paying the store for special placement in the customer's pantry? Once I pay the store they'll send people to customer's homes to put my products front and center in the customer's pantry even if the customer didn't buy them and if that leaves the customer without enough space for what they did buy then tough luck, what the store put there is locked down so only the store can move it and they won't. That's not fine. It's not the stores shelves, and nobody's paying the customer for special placement on their shelves.
Ah, but the argument might be that it's not the customer's line, it belongs to the ISP. If so, then exactly what is that bill the customer's being sent every month for then? We already have situations like this. If I'm renting an apartment the landlord still holds the title to it but it's my apartment as long as I'm paying the rent and the landlord isn't free to just do anything to it he pleases any time he pleases. If I'm making payments on a car loan the bank holds title to the car but it's still my car and as long as I'm making the payments the bank can't just come in and borrow it any time they please or have it repainted to a color they like or anything like that. In the same way, the customer's paying for Internet access and as long as they pay the bill every month it's their Internet access and the ISP doesn't have an unrestricted right to decide how chunks of it must be used (unless, as with the boxes that disable a car if payments aren't made on time, it's made completely clear up front that this is being done and why and it serves a reasonable purpose (use of that box after a payment has been missed is one thing, but if the finance company tries to claim a right to use them when they think a payment might be missed soon (even though payments are still current) the courts would reject that as unreasonable even if the contract tried to allow it).