Myth: Since wide ads (336×280, 300×250 and 250×250) are effective in many websites, it must also be doing the same thing in my website.
Fact: Not really. Every website has its own characteristics; you cannot just follow what people said and then hope that your CTR will drastically increase. Try to do your own experiments with various ads and placements. Perhaps ads unit that are not effective in another website are your most profitable ads.

Myth: It’s profitable to develop website that’s targeting high paying keywords.
Fact: Perhaps, if you really are a Search Engine Optimization expert. It is correct that when these high paying keywords are clicked, you will get a huge amount of money. But do you realize how many people out there who also think the same thing? I’m sure there are hundreds of thousands; and you will face bloody competition to reach the top position in SERPS (Search Engine Result Pages). Without top position in SERPS, there will be no visitor; without visitor, there will be no one who clicks on your ads. I have another suggestion for this approach, read it in How to Increase Your Google Adsense CTR.

Myth: High Traffic + High CTR = High Income.
Fact: It is a perfect equation if only there is no smart pricing. High income depends of several factors, such as smart pricing and what type of website you run. Some types of websites (such as forum) have high traffic but they do not generate many incomes from Google Adsense. Smart pricing also affects it. I have seen many websites with high traffic, high CTR, but totally low income.

Myth: Be careful if your traffic suddenly increases (perhaps because a popular website features one of your articles), Google might think you are doing spamming.
Fact: Nonsense. Google is able to detect your visitors from their IP addresses (if you are not net savvy, just imagine IP address as your phone number; every time you make a phone call, it will be recorded on your phone company). If you’re doing spamming, there is big possibility that all these IP addresses will be exactly the same. Beside that, Google is able to detect who your referrer is (where your visitors know your website from). If they find out that a popular blog/website is linking to your website, they will surely understand. So, don’t worry about this.

Myth: If Google suddenly bans your Adsense account, there is no chance you will be able to defend yourself.
Fact: Some people agree with this, but some other give contradictory facts. Many webmasters complained that Google never gave them warnings and suddenly terminated their accounts. In fact, Google even didn’t give them any explanations what their fault was. Strangely, some other webmasters gave contradictory facts. Firstly, Google always gives two warnings before they finally close an Adsense account. Secondly, if you can prove that you never break Google Adsense TOS (Terms of Service) such as doing click fraud, then they will reactivate your account.

Myth: Google Adsense will make you millionaire within a couple of months.
Fact: Wake up! It’s not time for daydreaming! You must treat Google Adsense as a real business. And just like another real business, it takes times and efforts to be successful.

Myth: Repeating visitors will stabilize your Google Adsense incomes.
Fact: Big mistake. In fact, repeating visitors even easily suffer ads-blindness. Since they regularly visit your website, they know where exactly you put your ads (except you rotate those ads everyday), and will avoid them. Getting new visitors everyday is more effective for your Google Adsense incomes.

Myth: The only way to monetize your Google Adsense account is by placing their ads in every website/ blog you owned.
Fact: Fortunately, no! There are many ways to use your Google Adsense ID (known as “Publisher ID”) now. One of them is by using it for “revenue sharing”. What is that? There are some forums that ask you to enter your Publisher ID when you register in their websites. They will use this ID to generate Google Adsense ads that will be displayed in every thread you participate in. If these ads are clicked, they will split the income: 50% for you, 50% for them. One of the forum that provide this facility is forums.digitalpoint.com

Myth: People who got tens (or even hundreds) of thousands dollars from Google Adsense must own a single website that is visited by millions of visitors a day.
Fact: Not all of them. In fact, many of them even admitted that they got those checks by developing many small websites. For them, it is easier to generate $40,000 from 40 small websites than generate $40,000 from a single website.