This is more into AI than Ads. AFAIK Siri uses Wolfram Alpha for its answers. Given the way Google's knowledge graph is advancing, it totally makes sense for them to build their own AI engine.
Google Knowledge Graph is based on Freebase.com. Google shut it down, last month. IBM relied on Freebase for Watson, so they acquired Blekko last month, a real web search engine & knowledge base startup. Microsoft already owns Powerset company that powers their Cortana. Apple needs a up-to-date knowledge base too, currently they rely on WolframAlpha and Freebase, afaik.
Shutting down Freebase was a big hit for many projects in the AI space, Freebase had 2,903,361,537 facts in comparision Wikimedia's Wikidata has just 13,924,224 facts - that's still a huge difference.
Shutting down Freebase was a big hit for many projects in the AI space, Freebase had 2,903,361,537 facts in comparision Wikimedia's Wikidata has just 13,924,224 facts - that's still a huge difference.
http://en.wikipedia.org/wiki/Freebase , http://en.wikipedia.org/wiki/Knowledge_Graph , http://en.wikipedia.org/wiki/Blekko , http://en.wikipedia.org/wiki/Powerset_(company) , http://en.wikipedia.org/wiki/Knowledge_Vault , http://venturebeat.com/2015/03/27/ibm-acquires-web-crawling-...