I can report that it has indeed made me happier, as compared to when the ads were "Click here, Millionth visitor, and win a prize!". The dragnet advertising is a constant assault on your intelligence.
It also helps that the targeted ads I am seeing are tasteful & well designed.
I adblock 90%+ of the time, but I let ads through on some websites.
Also, I like to research, in general. Which means I can often come across and get deeply into some very odd subjects and it seems there are some odd correlations out there in society. For example, after doing a bunch of research on different world religions and their origin stories, I started getting ads for the Mormon church, and strangely, for all types of gambling websites, destinations and attractions. None of this advertising was of any use.