The Webring is the way of a link exchange between sites of certain subjects. There are i.e. 1->2->3-> in setting by the participants of a webring links to each other in round..->1. This way of a link exchange isn't universal for increase of the quotation index because the search systems recognize blocks of a link exchange and don't take links into consideration during the calculation.
Services for organization of sites to webrings, for example, of webring.com, which took over bustle about support of the existing ones (now + more than 40 000 of them are there more narrowly) and creation of new rings exist in the Internet.