That might be at least partly solved by our Custom Wizard plugin. And if not completely it might get you most of the way with some additions. I’ll PM you.
Another idea, and again I wonder if this should be considered as a core feature, is allowing users to follow certain tags upon sign-up.
Most social networking services offer this: for example, upon signing up on Twitter, they pretty much beg you to ‘follow’ certain topics, etc. Pinterest does this as well.
Perhaps groups can be bypassed, since the goal is getting the user upon sign-up to have notifications on for a certain tag.
So what you really want is to get people to follow certain tags, either as a function of some user custom fields, or maybe something else. The custom wizard might have some solutions.
But you could also just tell them to go to the tags page and follow some stuff.
Maybe you want a page with some tags and checkbox to follow them.
It was just an idea. Groups still might be the best bet, since it’s the closest thing to a more formal micro ‘community,’ and that way tags/categories can be predesignated that they’re following.
From a UX perspective, there’s a reason those services cited above ask users to follow topics during the sign-up experience, and not after the fact, and that’s because engagement typically plummets after the initial experience.
So baking it into the sign-up experience is still very much needed!