> Another problem is the same C++ training ad would be served on every one of my site's pages. Magazines don't run the same ad on every page.

No, but they ran the same full-page BASF floppy disk ad or whatever at the end of the contents page every month for two years. Repetition in advertising has been a thing since the field was introduced. I can't believe you're only seeing it for the first time now. Even today, go pick up a Motor Trend and compare it to a Car & Driver (or Vogue and Elle, whatever floats your boat) and take a look. They're all running the same ads!

Now, sure, it's true that online ads afford the opportunity to saturate that print doesn't. But it's not any different at all. And it works! Which is why the advertisers (who, let's be clear, know their business a lot better than you do) do it.

I stopped running their ads. Their technique didn't work for me.