It definitely is important. As someone who works for web series on the PR/social side and then as someone who writes about web series, it's a great way to amplify your series for free.
What I would do, is potentially get someone on board to help you with that. There are great/easy ways to learn to also automate them as well so you're not having to do it every single time.
It gets tedious and sometimes you might feel like what you're doing isn't working but hashtags and just knowing where/when people are talking is key. If anything, you might want to consider joining #webserieschat every Wednesday a 1 PM CST, where a bunch of people come together to discuss tactics and things going on in the community!