I've said it before, and I'll say it again.
People learn to ignore online ads as irrelevant to what they are interested in. Soon after ignoring them, they learn to block them. Ad-based online revenue streams are a short-lived business model, due to go the way of the dinosaur fairly shortly.
Another way of looking at it ... Think the mid-1630s, Holland & tulips. Make your pile o'loot from the rubes, and get out as soon as you can. I did.
I never broke any laws, or ripped off little old ladies, either ... rather $BIGCO bought me out because my "portal" (as they were then known) was getting a lot of hits per day. $BIGCO went under soon after, during the dot-bomb crash. Me, I bought a horse ranch in Sonoma & am now "retired" to a life of sun-up to the following sun-up, 7 days a week, labor. I only touch computers & networking when my wife has her eye on a particularly expensive horse, or I need to buy a new tractor (water truck, whatever). I'm happy, which is all I ever wanted in life :-)