On the web, no one can hear you converse – or perhaps they can, but it’s not terribly easy to surface them and have a sustained, engaged dialogue around any particular topic.

Threaded comment streams do this to some extent, as do forums, message boards, and even social networks like Facebook and Twitter. But none do thematic or topic-based discussion well, according to Hubub‘s founders, hence the need for the startup.

Toronto- and New York-based Hubub launched in beta quietly late last year, and today it’s announcing its $8.5 million Series A round of funding. That money will help the company scale and add more engineering talent to its team to continue to build product, founder and CEO Peter L. Corsell explained to me in an interview. But it’s mostly business as usual, as the startup continues its mission of trying to build on what was started with the online forum, but never really improved since.

“Specifically what really gave us the idea was that we were watching the Egyptian protests, in the latter part of the Arab Spring and we looked at the way people were using Facebook and Twitter, which was both inspiring and novel,” Corsell explained in an interview. “Yet it occurred to us that there was also an unmet need to give a tool to rapidly convene passionate, engaged communities around a topic of interest.”

Thus was Hubub born, which is designed to build these communities, where users can jump in and contribute the best content, be it user-generated or collected from the best of the web, around specific topics. Hububs (the individual topic nodes created) are user-generated and user-curated, but there’s also a degree of automation where you can view auto-collected content around certain keywords, too, making this effectively an aggregation search engine, too.

“When you think about the future of search broadly, I see it bifurcating between what I would think of as more tactical queries where you have a question and there’s one right answer or a small finite pool of good answers,” Corsell said. “The other type of search is, if you Google for example ‘what were the most searched for terms in 2013,’ it’s topics: It’s ‘iPad,’ it’s Bengazi,’ it’s ‘Kate Middleton.’ What excites me about Hubub is as the community matures, it becomes a really great place to go to immerse yourself, in articles, in photos and videos and more.”

Other efforts attempting to build conversations around specific topics haven’t always fared too well: Branch nabbed a decent exit to Facebook, but even big league efforts like Google Wave fizzled quickly, and as Corsell himself notes, there hasn’t really been anything between the legacy (read: outdated) model of forums and the too fast-paced, stream-based vision of Twitter that manages to keep things on topic over a sustained period, with real back-and-forth.

Corsell thinks Hubub has the right mix of media, polls and sentiment analysis to make a real impact, and he says early traction backs up that belief. I’m still not sure that there’s a real need for this kind of platform between the existing social media giants, but Hubub’s investors in this round, which include a number of private investors, are definitely betting that there is. Hubub plans to launch its mobile client within the next few weeks, too, which could have a big impact in terms of validating the model.