The "No, thanks" window
The modal window has the hidden “No, thanks” in itself, because the desire to promote leads to more resentment towards the promotions. The offer will be then perceived of lower quality, because it's presentation was bad. The experience of the product is never only the product itself, but everything around it. The value of the product then might be determined by the weakest aspect around it, and this can be everything in the range from design to shipping and communication. The use of modal windows that are hard to close practically says that the presentational aspect isn't important to us. No amount of marketing can offset the effect on perception that the worst product aspect has.
Disallowing choice through making important links hard to notice means that future offerings on the site will need even bigger sales efforts, since all users have now warned their contacts of the potential pitfalls of using the site. Internet remembers everything and this can support or hurt site owners who follow bad practices—long after the fact.
If the design relies on people to have installed ad blockers, it's not right. The problem is then exacerbated when users start to accuse each other of not having installed such a blocker, when in reality this shouldn't have been made their problem. Designers can't simply submit work to their users this way. Any application that works on top of the browser and is required for the optimal operation of a site is a dependency, which constrains what users will be able to perceive from the vast pool of information. The desire to block one bad modal window once will then lead to blocking all other windows, entirely excluding the possibility that some of them might be designed well in the future. Good design eliminates assumptions and dependencies completely. If not, "No, thanks".