By a broad definition, sure, but I think when people talk about social media they generally talk about the major traditional social media networks that fall into predictable user patterns/behaviors. I voted 'no' -- I'd call this site a message board or forum. It's an old fashioned phrase (tho this is an old fashioned site), and there's a lot of crossover of functionality between message boards and what most would think of a social media site, but if I'm thinking of "social media" I'm generally thinking of the legacy social networking/media giants, and not so much small individual privately owned forum/message boards like this one.
There's a lot of cross-over functionality that applies to social media websites like, say, Facebook or LinkedIn, that also apply to things that nobody would consider Social media. Like, we use Jira for tracking projects and work progress at work ...... but Jira also has comments, and threads, and contacts ... and messaging ... and I can upload files and we can comment on them, and there's a network of contacts that are connected through my Jira channels, etc. But... nobody considers Jira to be social networking, it's work productivity. So if we think strictly by feature set and get too broad, we can easily include things as 'social media' or 'social networking' that would be better describe as something else.
Likewise with other sites, even huge ones, like Reddit, or services like WhatsApp. THey can broadly fall into the broad spectrum of "Social media," or "Social networking," but I think they're more specifically a link aggregator or a messaging tool, or like how imgur is an image host but it has social media features. NOw, obviously, there's some crossover with both ... Reddit subchannels can be run very similar to Facebook Groups, you can have members, and contacts, and messages, etc. Similarly, WhatsApp has a lot of crossover and it's even owned by Facebook which is undoubtedly social media. But I think when we paint with overly broad strokes and being expansive with definitions, it ends up missing the point.
Anything that encourages social interaction ought to be included in that definition. I mean, forums and chat services are what inspired things like MySpace and Facebook to up the ante and basically become forums with people you actually know.
I disagree with this because I think it's so broad that it makes it more difficult to talk about something. If it's just something that encourages social interaction, then Slack is social media; Gmail is social media; Outlook is social media; Medium is social media (or w/e)... And you could say "Sure! THose are all social media, they encourage social interaction!" But then we've lost a genealized understanding of what social media or social networking is, and it'd be more specific and helpful to say that Gmail and Outlook at email clients, Slack is a work messaging platform, Medium is a blogging service, etc. MAny of them share features from prominent social media platforms (or inspire features on those platforms), but I think we lose the effectiveness of words when we get so broad to rope everything in as social media despite if they share similar features.