Author's network: How old is the account? Do some background research on fans and followers: Who is in their network and who follows them? Who leaves comments?
Reliability (of author and content): Can the information be verified from other sources? Does the author have a Facebook, Twitter, YouTube, Instagram, blog, or personal webpage? What kind of content is showcased on these pages?
Contextual updates: Does the author usually post about this topic? If so, what do past or updated posts say? Do they fill in details as they occur?
Geography: If the blog features breaking news content, is the author near the location of the event?
Social media is a great starting point for brief mentions of studies, breaking news, company and industry updates, or statistics that link to a primary resource. Also check the blog/Twitter/YouTube, or other account for possible keywords to help you in your follow-up research.