I don't even consider ads, generally. I use an adblocker, UBO Lite, and the ones that aren't caught in the filter are just sort of ignored. I don't trust myself to be able to manage deciding on if a product is worth investigating and perhaps buying, being fairly impulsive, and so a blanket policy of 'don't buy what ads offer' and more generally 'don't click on ads' makes the most sense.

Newsletters aren't an exception. The only conceivable exception is when it's like 'Hey, I really enjoyed this newsletter' or affiliated interesting looking newsletters(eg I've looked at the other newsletters Nature has, which are linked to at the bottom of Nature Briefings), but those aren't really ads.