San Jose-based Adobe Systems said Tuesday afternoon that it has acquired Demdex, a developer of data management software for the online advertising market. Financial terms of the acquisition were not disclosed. Adobe said it would add Demdex to Adobe's Online Marketing Suite, powered by Omniture, to deliver more relevant advertising to customers. Demdex provides anaonymous audience data to web publishers and advertisers, to better target advertisements. Demdex was venture backed by First Round Capital, Genacast Ventures, and Shasta Ventures.