[lrem]

That's a train with a busy time table. Every software engineer who ever wrote a comment on the web, got an idea how to make our better at some point. And it isn't a problem with a high barrier to entry.

The interesting, for me, part is the antispam. It is also silly hard, for obvious reasons. A big part of why Disqus is hard to replace is that they're doing a great job with it. Only once you clear that bar, you can think of successful monetisation.

[FalconSensei]

Monetization can also be a problem if you don't provide enough tiers for users (same as any hosted web analytics alternative to google analytics).

I.e: my blog has like... 200 visits per month? I don't have comments right now - only link to twitter/reddit - but I expect I would have a dozen comments per month, tops. At this point I don't even care about anti-spam, but if a tool asks me $10 a month, I can't justify paying it. Make it $1 and I'm in.