Will I continue to invest lots of time creating posts if I don't have indications that there is a value?
First of all I need to ask, do you have any other experience with creating content which was appreciated by wide audience?
If Steem is for someone a first attempt to make good and popular content, then... everything can be really confusing. Truth is... that creating a good content is not easy in general and it is even more difficult in such difficult environment like Steem.
In my experience good content without proper marketing very rarely becoming popular. It happens but it requires tremendous amount of patience from author.
And a proper marketing of post... is a topic for whole series of posts (and for sure, I am not an expert about that)... but just for comparison... I can spend 8 hours writing post, and next 4-6 hours to promote it (very often I promote my post even before a publication, trying to find people, which would like to read what I am gonna to write).
How can groups be brought together beyond just using specific tags?
Easiest thing would be to ask is there any place where very specific group of people already gathers. This is decentralized social media. People have chats, groups, discords, telegrams and dozens of different places.
How can you even know what tags make sense for your content?
Observe other authors, which tags they use, and.... ask best authors, which tag is best for your post. You could even have a line at the end of every you post, which says:
Do you think my tags are ok? Or maybe I should use some other tags,which would be more appropriate for this article. Let me know!
To answer your question, no, not a lot of experience. That's an excellent point.
Related to marketing, I think that's my bigger challenge. The confusion about how to market on this platform is a difficult learning curve. How to get started is certainly not apparent without randomly finding good posts at this point, since I have not yet figured out a good strategy to find the gems that I struggle to find now. What I've read so far can sometimes contradict.
Decentralization is a strength of this platform but also makes it very difficult to get started on it. I'm sure I'll get it figured out eventually, especially since people seem willing to engage.
So far your recommendation about how to pick tags is exactly how I've been doing it, so that's helpful to know there isn't some other special place I don't know about to find out what tags are effective.