https://motherboard.vice.com/en_us/article/mbkgn8/dont-rent-a-modem-from-comcast

Millions of consumers continue to pay cable companies like Comcast a monthly fee to rent a modem or gateway (a combination modem and WiFi router)—and Comcast keeps proving that's a really bad idea.

From the company’s arbitrary and unnecessary broadband caps and overage fees to all manner of sneaky below-the-line surcharges, Comcast has made an art form of advertising one price, then socking consumers with significantly higher rates once the bill comes due. As a result, the company is facing several ongoing lawsuits for misleading billing. One of the most profitable surcharges for America’s biggest cable provider is the fee it charges users to rent a modem, router, or gateway. Comcast has slowly but surely jacked up this rental fee over the years. After yet another price hike at the beginning of 2018, Comcast now charges customers $11 a month to rent both modems and gateways. Over time, users wind up paying Comcast significantly more money than the modem or router is worth. One analyst estimated that Comcast makes between $275 million and $300 million each and every quarter just from these rental fees. And given that Comcast buys hardware in bulk, it’s estimated the company pays as little as $40 for each modem. Those turned off by Comcast’s reputation as one of the least liked companies in America should do themselves (or a loved one) a favor and stop unnecessarily padding the company’s bottom line. While the company doesn’t like to advertise the option, users have the ability to buy their own modem or router, provided it’s on the company’s list of acceptable devices known to play nice with the Comcast network (the same is true for Charter Spectrum.) Many of these devices can be bought for a pittance via online retailers, and even less if acquired second hand. Unsurprisingly, Comcast’s historically abysmal customer service can sometimes make this more challenging than it should be. For example, the company has long had a nasty habit of charging users the rental fee even if they own their own modem, requiring users keep an eye on their bill.