advertising

 advertising  is a common business-model for websites, especially silos, but also on some IndieWeb sites.

IndieWeb Examples

 * zeldman uses The Deck to serve ads
 * daringfireball uses ???
 * uses ethicalads.io

Facebook
Facebook uses their own ad system.

Example ad for example.com:

http://zegnat.net/tmp/example-com-ad.png

Ad models can be exploitative
Advertising based business models are to be avoided as they are exploitative.
 * See: http://blog.whatsapp.com/index.php/2012/06/why-we-dont-sell-ads/

Counter argument:

Nonetheless many companies who provide a "free" service, are actually ad-based businesses
 * Most silos
 * All known aggregators
 * All known general web search engines

May cause UX failure
Lazy loading ads which reflow the page (i.e. an ad at the top that doesn't take up space to begin with to avoid an awkward blank area at the top of the page) can cause UI elements to move and thus may result in the user clicking on something they did not intend to. E.g. (likely artificially constructed example for illustrative purposes)

mp4 video