If I am known as 'into' something, then the likelihood that someone who isn't also into that same thing will come up with a good gift is shockingly low. I bake bread, for example. A book of 100 bread recipes is basically dead weight to me. I have a friend who is really into knives of various sorts. Even though I'm happy to drop a couple of hundred dollars on a gift (they've been super generous to me in the past), I'm not able to pull the trigger because I feel like the facebook-ad-quality-knives are almost certainly not what they would value.
Although... I suppose the point of the article on this point is that if I just asked my friend, they would receive the value of the gift (since I would just be proxying the purchase for my friend, and gifting them the cash). So my refusal to do so is just me maximizing for my own selfish gift-giving goals. Interesting.