San Francisco-based instant messaging firm Twitter said Monday afternoon that it has acquire a small Portland, Oregon startup, Values of n, and hired on its founder as part of its engineering team. Financial terms of the acquisition were not disclosed. Values of n was founded by Rael Dornfest and funded by First Round Capital, Magnus Ventures, and Sherpalo Ventures. The firm's software allowed users to put "stick notes" on calendars, web pages, and elsewhere on the web. According to Twitter, the sale came because Dornfest had decided that Values of n was not going to meet its huge expectations as a standalone business, despite a loyal following.