Ask.com has now acquired the Lexico Publishing Group, which owns a bunch of reference Web sites including Dictionary.com, Thesaurus.com, and Reference.com. Ask's move is aimed at distinguishing itself from Internet search giants like Google, Yahoo!, etc. The acquisition made sense to Ask as more than 30 percent of searches conducted on their search engine are in the reference category, the company said.

According to comScore, more than half-a-billion monthly searches worldwide consist of dictionary, thesaurus, and encyclopedia queries. So, the acquisition is expected to grow Ask Network's user base by 11 percent, increasing its user count to over 145 million (not duplicated) monthly unique users (UUs) worldwide.

If expectation turns into reality, Ask network would become the ninth-largest Web property in the world, which is even ahead of Apple and Facebook in monthly UUs worldwide.

However, Ask clarified that a sharper focus on reference tools doesn't mean it is abandoning its role as general, multi-purpose search engine. "This acquisition just is the first tangible piece of the puzzle," said Jim Safka, chief executive officer of Ask.com.

In addition, Ask plans to plant some of its search engine results on the reference sites in an effort to make known its technology to a wider audience. Some of the material from Dictionary.com and other reference sites will also be featured on Ask.com.