YFly is a website that was advertised on YTMND for a week (between April 26 to May 1), when Max had made his first two "Night of the Unicorns" gags. This advertising included a top-right watermark on every YTMND, an appearance on the list of sponsored YTMNDs, and a banner and images appearing under the Recently Created list.
While some users made sites mocking or complaining about the YFly ads, others simply used Firefox and AdBlock to hide them instead.
Images under Recently Created list
During that week, YFly showed a wide blue banner under Recently Created, and images (some slightly not-work-safe) directly below that banner. The images included monkeys with one of them having their head replaced with Osama Bin Laden's head, another one with a black person (Perhaps Bubb Rubb) pointing out his middle finger, and lastly a fat woman taking her pants off and a rocket censoring the privates.
One part of the site YFly was advertised on was a spot on the Sponsorships list. It appeared as a "$250" spot titled "YFLY Smacktalk! (offsite)".
humanbomb decided to create a site and sponsor it for $281 to push YFly down the list, but did not succeed; the spot stayed on top, even with a smaller dollar amount. max revealed that the spot's placement was actually determined by him:
i just had to recode the hack to make YFLY show up second. i was hoping no one would do this.
max later added,
$250 is not close to what YFLY is paying for the sponsorship.
When humanbomb later asked what the actual sponsorship value was (intending to "pay more" and out-sponsor YFly), max replied:
humanbomb i doubt you would be willing to drop five figures on it.
Because the YFLY corner ad was placed at the top-right corner of YTMNDs, many hardcore PTKFGSers were convinced this was the final harbinger of doom for their PTKFGS sites, whose PTKFGS logo originally inhabited that corner. Keatonkeaton999 eventually made a YTMND expressing these concerns, . For the archived version of when it did make sense, go here: http://web.archive.org/web/20070425052308/http://this-site-wont-make-sense-eventually.ytmnd.com/.