I think and believe adsense is a scam, at least to smaller websites.
I got kicked out from their program just because they said they detect click fraud.
They just kicked me off their program and there was no evidence any fraud taking place. Just their word.
I felt scammed. In fact, that is why i do not accept pay / click ads anymore. Or the like "if customer makes a purchase using your link you get €€€"
That is a scam too. One purpose of the ad is to make who ever sees it to remember it. If they do not use the service now or buy the product immediately, they are biased to do so later if you need such service or product. That is a simple fact of advertizing.
Internet can be a good place to do business, but as i have recently noticed soime foreign companies are trying to sell their product using some automatic translations. They look absolutely crap.
I have one quideline, if it is not grammatically correct, it is scam.
Someone might say that about my english skills, but...
That is one way i weed out the web garbage.
A good ad can boost your sales. Don't underestimate the value of one ad. It is worth a lot more than just a click.
EDIT: have you ever taken a survey on a website who tries to improve their service?
One question almost always is "Do you remember seeing this ad"
That is just one way of making sure they have formed their ads correctly. If you do not remember it, they can always change it so you do...
One trend for internet business can be seen from the newspapers. Newspepers are more or less losing readers when younger generations learn to use internet. Just go to any newspapers website and see yourself.
Some charge you few €uros for letting you read a "virtual newspaper"
Some only give teasers or stripped down versions of their headlines (wishing you go and buy todays paper) and some just let you read it all for free. Those who let you free probably has a lot of ads.
A computer store here only keeps the cheapest crap on the shelf. The more expensive stuff can be ordered withing two days delivery.
One good thing for e business is you don't have to keep large stocks. You can order stuff from the importer as you go and get customers.