In open access publishing the author retains the copyright when the publication has an open license.
Research has shown that open access publishing increases the number of citations that articles receive, in some fields even significantly (Swan, 2010):
Open access publishing policy of the University of Oulu.
Open access publishing refers to the free dissemination of scientific knowledge. A scientific publication is openly accessible when both the scholarly community and the general public have free and unrestricted access to it on the Internet.
Open access publishing increases the visibility, use and impact of publications.
There are different ways authors can provide open access to their article:
Some directories of gold OA journals