My ISP doesn’t have anywhere near as shady marketing practices. Does yours regularly ignore do-not-call and do-not-mail requests? Do they send misleading envelopes that don’t have their brand on the outside? Mine (AT&T) doesn’t.
AT&T is nortourius for this in my area. They will send letters on cardstock with handwritten font, an obscured return address, and a stamp that looks hand placed. No branding until you actually open it.