"It takes our scale to a completely different level," Weiner said on "Squawk Alley" hours after the announcement. "The combination of our two companies, having Microsoft behind us, just enables us to realize the things we always dreamed of doing, and so we're excited about it."
Moody's Investors Service placed Microsoft's "AAA" rating under review for downgrade following the deal announcement. Standard & Poor's though, reaffirmed its "AAA" rating, and said it maintains all other ratings and a "stable outlook" on the company.
The acquisition would allow LinkedIn to create a social fabric that can be "seamlessly integrated" with other areas of Microsoft, like Outlook calendar, he said. The companies started talking about a deal in February, after Weiner said he noticed a clear pattern among tech giants' earnings.
"You look at Google, Apple, Microsoft and Facebook, and within the span of a few days after their earnings reports, collectively those companies increased their market capitalization within somewhere of $100 billion," Weiner said. "It used to be that scale was hundreds of millions of users and billions of dollars of market cap. Today it's billions of users or customers and hundreds of billions of dollars of market cap."
LinkedIn will fit into Microsoft's cloud by bolstering Office 365, helping connect the world's professionals and make them more productive, Microsoft CEO Satya Nadella said.
"These professionals are using Office 365 on one side, and LinkedIn on the other side," Nadella told CNBC. "That's one massive opportunity for us to increase engagement in both."
Nadella pointed to a potential for Microsoft Outlook users to integrate LinkedIn information. The news feed on LinkedIn for example, might now include what projects someone is working on, and what their Outlook calendar looks like for the next two weeks.