Regarding the intro of the article: I agree, it's important not to heed any advice that tells you that you just can't advertise or market to any particular demographic.
Advertising and marketing are essentially universal truths. If you are having trouble reaching someone, it most definitely isn't because "ads just won't work on them."
Also many websites the product is not showing what it does on the front page. Many times they extol how amazing the product is. Best thing ever, customer abc built more whatamdongles with it, etc, etc. But what does your product actually do?! How would I use it? When buying a tool I am many times not buying fashion. I am buying a tool that does something. Be upfront what your tool is. If you are 1 of 5 competitors explain what your tool does that the others dont. Dont make me dig around on your site to find it or sign up for something just to look at your docs. It shows me you are not serious about helping me, other than helping money out of my wallet, and trying to setup a time to talk and waste my time.
Advertising and marketing are essentially universal truths. If you are having trouble reaching someone, it most definitely isn't because "ads just won't work on them."