People seem to think that the best way to get noticed on social media is to be active everywhere. It's not.
But when we start to get serious about communicating with people – as a parish or an organization or even as individuals – we often make a mistake very similar to this. We see all the available channels and we think that it's important to be active in each of them. Instagram, Facebook, a blog, a Youtube channel, &c. We want to reach as many people as possible and so we rack up accounts on various services like we're collecting Halloween candy.
This is starting from the wrong end. When you attempt to use every available medium, you're almost certainly doomed to spread your content too thin, and make it more difficult for those who are interested to keep up with you. Very quickly you'll find making your social networking rounds a dolorous chore.
I fully agree with Sid here. If you're constantly trying to post different content everywhere, you'll never produce enough to interest someone on just one platform. The other issue is that if you're posting the exact same thing (like a photo on Instagram, SnapChat, Twitter, and Facebook), there's no reason for people to follow you in all those places, and they can just stick with one.
In the end, this is part of the reason why I'm not (at the time of writing) actively using SnapChat, why I don't ever post on Facebook, and why my Instagram usage is waning: I'd rather focus on the place where I know I have an audience, and produce content there to the best of my ability, and if people — such as family and distant friends — feel like they need to see more of me, let them put the effort in to finding me somewhere.
In short: use the social networks that you're already on and have an audience on, and don't go around to other services unless you can see the real benefit to it. Don't waste time giving a little bit of content to each service, and please-oh-please don't post the exact thing in every single social network.