There are three types of wikispam: advertisements masquerading as articles, wide-scale external link spamming, and "Wikipedian-on-Wikipedian" spamming or, "canvassing" (also known as "internal spamming" and "cross-posting"). Articles considered advertisements include those that are solicitations for a business, product or service, or are public relations pieces designed to promote a company or individual. Wikispam articles are usually noted for sales-oriented language and external links to a commercial website. However, a differentiation should be made between spam articles and legitimate articles about commercial entities.