Stripe is a great service, but I get the feeling their PR company or marketing department promotes extensively here (Makes sense since its the target audience).
Seriously: they're on my blog because of the reasons in the post. My blog's on HN because, well, that's a complicated topic but suffice it to say that it happens with a fair degree of regularity.
We try not to post on HN unless we actually think people on HN will like the content (and we've argued internally before and decided not to post stuff to HN because it didn't seem useful enough).