Actually I worked for a magazine. When they got advertising campaigns on their website, they would promise unachieveable impressions. In one case, their website had a total of 50k impressions per month, and they sold a display ad campaign promising 300k impressions in that month (which is impossible). They had to buy fake traffic to reach that number of impressions so the client would pay them.
Also they promised clicks, and had to fake that too. But that's for another episode.
Another client was an advertising agency, they promised their client an increase of their website traffic by 10% at least. Some of their client sucked and they had to fake some traffic to reach their contractual agreement of the "at least 10%". That's because if the contract is not filled, they don't get paid.
You can also manipulate analytics to make your site look more in demand. There are many public tools to estimate a website's traffic. Sometimes I'd get people tell me how their site gets 400k impressions per month, but then on a free public tool it shows they get 50. It's inaccurate and might seem unimportant, but I had some bot send traffic to my previous company's site. When meeting with clients who didn't think my company was in demand, i would pull up one of those free tools, and show him we get 9k visits per day for a marketing service firm, so obviously we know what we're doing.
