This is a big US/EU cultural difference in CS. In American CS, in many sub-areas, conferences are considered the top place to publish: CHI, SIGGRAPH, NIPS, etc.

This is a big US/EU cultural difference in CS. In American CS, in many sub-areas, conferences are considered the top place to publish: CHI, SIGGRAPH, NIPS, etc. are basically the most prestigious place to publish, and are frequently cited. In some areas the journals are actually less prestigious: there is no HCI journal that matches ACM CHI's impact factor or name recognition. And many AI journals are considered worse then AAAI or IJCAI as publication venues (though JMLR and JAIR are well-respected journals). But in Europe, it's more similar to the way it is in other fields in the US, such as physics: conferences are considered a fine place to present small bits of work, or work in progress, but not a proper archival publication for major results, which should go in journals. Journal articles get the main prestige and are what's expected on a CV, and citations to journals are strongly preferred over citations to proceedings. This leads to an interesting situation where some prominent tenured professors in the U.S. would be weak candidates for European faculty positions, and vice versa.