Everyone knows about the big Internet scams: the e-mails advertising diet pills, the proposed Nigerian bank transfers. But we tend to overlook the milder forms of truth-stretching that have come to shape online living, and it’s hard not to. They’re often perpetuated by big and reputable companies, like Apple, Seamless, and Amazon.

Take search. General search sites, like Google and Bing, are pretty straightforward: you type in a query and get results ranked by some measure of relevance; you also see clearly marked advertisements. This experience tends to shape our expectation that searches deliver relevant results. But the same search on sites like Amazon or Seamless turns up not only relevant results but disguised advertisements, as well. As George Packer recently wrote in the magazine, “Few customers realize that the results generated by Amazon’s search engine are partly determined by promotional fees.” GrubHub Seamless, the merged food-delivery engine, recently revealed in an S.E.C. filing that “restaurants can choose their level of commission rate … to affect their relative priority in sorting algorithms, with restaurants paying higher commission rates generally appearing higher in the search order than restaurants paying lower commission rates.”

These practices seem to run afoul of Federal Trade Commission policies. The Commission clearly declared, in 2013, that unlabeled ads posing as search results may be a form of consumer deception. Sergey Brin and Larry Page, Google’s co-founders, explained the harm of such a practice first (and best) back in 1998: “We expect that advertising funded search engines will be inherently biased towards the advertisers and away from the needs of the consumers.” In other words, people will buy stuff not because it is actually better but because it’s what turns up. Of course, that didn’t stop Google, in 2012, from making its product search, Google Shopper, a pay-for-placement service, albeit one with disclosures.

Another pillar of online commerce is user reviews, found on sites like Yelp or Amazon, which have revolutionized how many people shop. (The last time I bought a camera lens, I chose the model based solely on the fact that it had two hundred and thirty-eight five-star reviews on Amazon.) Unfortunately, more and more product reviews are now fake, and some earnest testimonials from bloggers are paid for. Last year, the New York Attorney General’s office discovered a spa on Craigslist offering ten dollars for a positive review to anyone with “at least 10 friends on Yelp.” Larger operations outsource fake reviewing to regions as far away as Eastern Europe and South Asia. No one knows how widespread the problem is, though some people have tried to guess. The problem compounds itself: when a company starts using fake reviews, its competitors often feel they need to do the same. Eventually, everyone is corrupted, not unlike cycling in the Lance Armstrong days.

Last year, the extent of the problem was revealed when the New York Attorney General’s office, soon after setting up an undercover yogurt shop, found itself fielding offers for fake reviews from companies with names like Eboxed and XVIO. New York’s Internet Bureau also investigated businesses that wrote their own reviews; among the findings were a hundred and seventy-five self-written reviews for dancers at Scores, a gentleman’s club.

Buying products online also leads to what can be called the buy-button scam, which is perpetuated even by top sites like Amazon and Apple. The other day, I decided I wanted to stream “Iron Man 3,” and Amazon told me I’d have to buy it for $14.95. It is, in fact, a common practice to present a “buy” button for movies, e-books, and digital music. But when you “buy” these digital goods, the companies maintain that, despite the big “buy” button, what they gave you is nothing more than limited permission to use it—based on fine print that creates a license, not a transfer of ownership. If Apple or Amazon can offer only what amounts to a long-term lease, the button shouldn’t say “buy.” It’s misleading.

The buy-button scam stings when it comes time to sell. Say you spent tens of thousands of dollars over the years building an extensive collection of movies on Amazon or songs on iTunes. Try selling your collection: you’ll find that what you “bought” is now worthless. If you’d spent that money on physical books, records, or CDs, you could resell them later. The would-be markets for used digital goods, like Redigi or eBay, have been sued for copyright infringement, on the premise that the goods being resold were either never sold in the first place or based on the technicality that every transfer of a digital good creates an illegal copy. Either way, you’re stuck with something that you supposedly bought but that you cannot sell.

Individually, none of these little lies are ruinous. But they add up, and they take both an economic and a cultural toll. One of the great promises of the Internet was that it would be a better engine of commerce: more products, at better prices, with more accurate reviews than old-style retail. That is a promise that has been, in many ways, delivered, but it’s one that’s threatened by too much stretching of the truth.

Photograph: Lightmax/Getty