The basic principle of EasyList is that its "filters must remove adverts". However, several discussions, usually with website owners, have highlighted an obvious issue: "advert" has not been precisely defined. A topic was therefore opened in the new EasyList policy forum and culminated in the definition of an advert as "the promotion of third party content in return for goods or services". This has several implications, as explained below.

"Promotion"

Specifying that an advert must promote means that a factual link (e.g. "Adblock Plus is a Firefox add-on.") cannot be an advert as it lacks a marketing aspect. Furthermore, an independent review is also unable to be an advert because it critically examines all facets of the content, not just the positive aspects.

"Third-party"

The aim of a website is to entice people to read more of its content, which visitors presumably desire to do, as indicated by their presence on the domain; they should therefore not be hindered in doing so by a filter subscription. Whether websites are third-party or first-party (what happens if one person owns two domains?) is a question for the EasyList authors to consider.

"... in return for goods or services"

An important question that has been raised is whether an advert requires the exchange of money, to which I would respond that it is not an essential element. Money may be one of the goods supplied, but there may also be services provided in return. Therefore a link to, say, a web host would be removed if this is a sponsored link required as a provision of service, but not if the description is merely factual, as this would not be promotion.

This definition includes link exchange schemes, whereby websites reciprocally exchange logos and links to the other domains for no other benefit, which Tarun, a website owner himself, claimed was not worthwhile removing given the large number of domains which use the link exchanges and their comparatively unobtrusive nature. After further discussion it was agreed that, provided links exchanges are unobtrusive and free of any tracking parameters, they will not be specifically removed by EasyList.