What the fictional high tech advertising hoarding above was doing was showing advertisements relevant to what the passing individual was thinking about. And of course all that was science fiction. But advertising relevant to what the shopper is thinking of and searching for is already here. It is called "Contextual Advertising". And it is so remarkable that I indulged in a little "science fiction" above, to bring it to your attention.
Thousands of Internet Newbies have bought such nonsense. Just as a surefire way of making money during the Gold Rush was to sell picks and shovels, a surefire way of making money nowadays is to market "Adsense Nonsense".
Contextual Advertising works very well for advertisers since it matches the information on the page and may lead to exactly what the shopper or surfer was looking for; it works for publishers and webmasters since it can serve WebPages devoted to virtually any subject. And the shopper frequently gets exactly what they were looking for.
But the Internet newbie who thought that putting Adsense on their blog or website was going to lead to a high income is usually disappointed as months go by and single figure earnings stubbornly persist.
In many cases Adsense may not be the best monetization option. The only way to know is to try various options and track and record the results. Many webmasters have found affiliate programs that pay them better than adsense.
Contextual Advertising is a clever and effective tool. Whether or not it is appropriate on a particular website or blog is a moot point. The only proper advice to a Newbie webmaster or blogger is try different advertising alternatives from Clickbank, Commission Junction or even Amazon and find out for themselves which works best for them on their site for their niche.