Web Science/Part2: Emerging Web Properties/Web Search Ecosystem/Understanding the problems with Web SPAM/quiz

1 Which of the following might be the reason for people to creating a link farm or link SPAM?

	Manipulation of the ranking algorithms and driving relevance to certain landing pages.
	Increasing the conversion rate of an internet service.
	Increasing the organic search traffic a certain target site is receiving.
	Increasing the paid search traffic a certain target site is receiving.

2 Why is link SPAM harmful to the business model of search engines?

	It is not harmful to the business model of search engines. since there is no connection to advertisement revenue.
	The search index is growing and containing useless information (rising costs)
	The computation time of pagerank will rise (rising costs)
	IF SPAM is not detected displaying search results will cost more time lowering the user experience of the search engine.
	The promise of the search engine is that it will bring the user to the most relevant content and SPAM does not make the content more relevant. (lower product quality)

3 Why is it hard to detect link spam?

	similar to click fraud it is even for a human hard to decide what the Intentions of a person putting one or more links was.
	detecting certain patterns in graphs which are typically followed by a link farm is an NP-complete problem.
	because spammers use bot nets and crowed sourcing to place links on blogs and wikis.
	The entire link farm is usually placed on one domain and it cannot be said what the intentions of the domain owner are.