So are advertisement good or bad? There’s no fixed answer. One view says it’s great cause advertisers have to pay for ads—so only sellers who believe that their own products/services are of good quality will use ads (if ads price and the ads market adjust appropriately)—then ads become informative and useful signals, and they would help consumers distinguish valuable products out of the sea of alternatives. Another view is that ads are more like competitors for attention—and it becomes a bad equilibrium now when seller would have to buy ads to at least get any attention.
Nevertheless, it seems now the market is a bit overly saturated (with a lot of money flowing) but yet mismatched (a lot of efficiency too) cause now there are ad blockers that pays you to view ads:

Pie Ad Blocker: Browse ad-free with Pie Adblock and earn cash rewards for the ads you choose to see.
One the good side, this ‘Block Ads, Get Paid’ model seems to be giving user back control over ads and privacy (here’s a video of their founder explaining their business model). On the other hand, I learnt about Pie because my YouTube ads showed Pie to me, meanwhile Pie claims that they can block YouTube ads…
