That's likely the difference. My wife follows people with similar interests, rather than only people she knows, so undoubtedly sees more of it.

Unfortunately it does happen. One of my coworker's mothers writes a food blog and he asked if she could follow me because she likes my photos. I said of course, and that she didn't need my permission. I followed her back out of courtesy, but then I started seeing occasional posts about "Certified Angus Steaks" and said nope. Good for her for getting money, I guess, but I don't want any of that.