[ Thanks to SeanParsons for this link.
]
“While browsing the Internet the quality of the service you
receive may be degraded by various factors such as adverts &
maleware most of these undesirable elements are simply annoying,
and to dial-up users in particular are costly, but some may be
serious security threats.“Many commercial web sites sell advertising space. The
unobtrusive adverts are small text-based adverts that neither
interrupt the flow of the site nor masquerade as anything other
than an advert…”