Running ad block, was confused why every 3 slides there was just this generic black and grey wavy pattern.

tl;dr install ad block

Yes, it all makes sense now! I love AdBlock so much : )

No, they're not.

If I wanted to buy something right now, I wouldn't be reading HN, I'd be browsing Amazon or whatever site sells what I needed to buy.

A properly targeted ad is useful. By definition, if the ad works on you then it did something useful for both the advertiser and the person who saw the ad.

Ads obviously sometimes work, or else no one would do ads.

It does, however, help pay for the content you're consuming.

I already covered that in another post: https://news.ycombinator.com/item?id=5459646

ads also serve to inform you of the existence of products

Yes, how rude that a website operator wants to monetize their content.

Like everything else, there are smart and stupid ways of going about this legitimate objective. This is an example of the latter.

People will put up with a lot to get to a piece of content that's sufficiently compelling. This probably makes more money than a "smart" option.

And what would the smart way have been?

well. I'm no expert, but I can sure take a shot of some things you might want to avoid!

   *Not marking ads as ads
   *Presenting advertisements with the same presentation inline with normal 
    content, potentially confusing the reader.
   *Assuming that no one would block the ads
      -or recognizing they would and not caring
   *Not making use of the space in the... article!

I did not notice I could scroll down, either. Why didn't they put the ads there?!

Then he should charge money for it.

Of course he would never do that, because the content he added simply wasn't very valuable at all, and he's primarily saying, "Hey, look at what some other guy did! And while you're at it click on my ads!"