The notice cited "an inability to secure additional financing" as the reason for the closure.
Feed and Suck.com merged last year, forming Automatic Media with financial backing from Web portal Lycos.
Six years ago, Feed came onto the scene, publishing bimonthly issues on the Web that focused on media, pop culture, technology, science and the arts. The e-zine provided an exploration of in-depth topics, ranging from the commercialization of religion to the mythology about the American West.
Feed's founders, Stefanie Syman and Steven Johnson, posted a notice Friday to readers, saying that the site has halted publication and would be providing "reruns" over the summer as it looks for a new home.
"We are feeling the effects of the recent chill," the founders wrote on the Web site. "As of today, we are in suspended animation, cooled to a temperature at which our metabolic rate is near zero."
Suck also posted a notice, saying that it "has gone fishin'."
Automatic Media and Feed could not be immediately reached for comment.
The closure comes as numerous online publishers face consolidation. On Thursday, AOL Time Warner said it plans to buy Business 2.0, with the bulk of the magazine's editorial staff joining the pool of laid-off employees. Under the deal, Business 2.0 will merge with its larger rival, eCompany Now, but retain its name for the combined magazine.
Last month, Red Herring Communications, which publishes Red Herring magazine and a Web site, announced its third round of layoffs despite receiving $15 million in funding. In February, Standard Media International, publisher of New Economy business weekly The Industry Standard, slashed 69 jobs, or 17 percent of its staff, following with another 10 percent reduction three months later.