That doesn't work. Before Bayesian filtering and Gmail, 90% of my mail was spam. The people who did it knew that it was wrong, they just didn't care. $$$ > almost anything.
But irritating popups will ensure many will never come back - you've forever lost your opportunity to even attempt to sell me something. Seems so illogical
When browsers and search engines fights back against crappy web content I suspect we'll see change.
Arguing that etiquette should be observed when you have a lead / sales generation flow doesn't work.
Depends on which customers you want.
Usually some out of touch marketing, SEO, advertising, etc. person. Most web developers aren't the decision makers in situations like this.
Or that monstrous dialog Facebook has on its pages asking its visitors to join Facebook. Annoying on desktop, supremely annoying on mobile. Just another reason I usually don't bother clicking on Facebook links.