n. A sharp and often overwhelming increase in a website's traffic, particularly after the site is featured on Slashdot.
2003
As publishers, we long for those times when Internet fate smiles upon us, bestowing a mention on slashdot.org, an act that usually precipitates a favorable influx of traffic known lovingly as the "slashdot effect."
2002
While Rob—don't call him Robert—Malda may fit the irreverent hacker stereotype, his finest hack does not. Malda is founder of Holland, MI-based Slashdot, a Web site cum online community cum Internet Zeitgeistmeter visited by more than 250,000 surfers daily. What started in 1997 as an online hangout for Malda's cronies to trade banter on geek subjects is now "the number one site for tech news and geek ranting," according to the Washington Post. Contributors recommend news items to Slashdot, where Malda and his small staff create links to the stories and write introductory paragraphs. Readers post comments, which are then graded by other readers. Many times, Web sites whose addresses are cited experience the "Slashdot effect"—an increase in traffic so sharp that their operations sometimes halt.
1998 (earliest)
The microsoft.com website was offline part of yesterday as a result of the so-called 'Slashdot Effect'. Yesterday morning, Rob Malda (aka CmdrTaco) posted an article on his Slashdot.org "News for Nerds" website. The article linked to a page on the Microsoft website that announced Windows NT 5.0 would probably be delayed until early 2001. Tens of thousands of nerds visited the page and brought the NT-based atbd.microsoft.com website to its knees.
I've included an earliest citation for this phrase, but I don't have much confidence in it because the phrase is preceded by the "so-called" qualifier. This tells me that the phrase was in use prior to July 26, 1998. I suspect the phrase was coined on Slashdot itself, so if some "Slashdotter" reads this and knows the true origin of the phrase Slashdot effect, I'd love to hear it.