> newspaper advertising has always been a low-return-on-investment marketing avenue

Back in the 1980s (in the Datalight/Zortech days), the only game in town was advertising in computer magazines. We knew it worked because the day the monthly mag appeared on the shelf, we'd get a big spike in sales, that would then taper off through the month. It was fairly easy to correlate which computer mags mattered, how ad placement in the mag affected results, and how the size of the ad worked out.

For example, we learned to never bother advertising in August. Programmers apparently all went on vacation in August :-) but September would be a huge month for us.

I tried print advertising in the aughts, but there was literally zero return on investment.