Media reports cited Hasting's post, and Netflix stock jumped following the announcement.
Companies generally announce news through press releases or regulatory filings to avoid violating the disclosure rules.
In a separate Facebook post on Thursday, which was first cleared with regulators, Hastings argued that companies should be allowed to use social media to make public announcements.
"We think posting to over 200,000 people is very public, especially because many of my subscribers are reporters and bloggers," he wrote.
He also argued that the fact that Netflix had surpassed one billion viewing hours was not "material" to investors and the company had already blogged that it was close to passing the milestone. He said that although the stock price rose the day of his announcement, it was likely driven by a positive research report released the night before.
"We remain optimistic this can be cleared up quickly through the SEC’s review process," Hastings wrote.