I like the minimalist design of the site, and I think your idea is the most visually appealing of all the default avatar options out there.

Some ideas:

Landing page:

- Add at least a quick blurb / product explanation to give first-time-visitors a quick, visual idea of what the product is (maybe even an alice/bob style demo conversation).

- Have more descriptive action choices "ready? start now for free" and "Learn more" instead of just "about/configure". About pages are somewhat ambiguous and can sometimes just be about the company / the people behind it instead of the product explanation, you're basically giving first time users nothing and hoping curiosity prevents them from bouncing. I'd say give them at least a bit of a hook to get them to venture further.

About page:

- Enlarge and really highlight the alice/bob chat box -- this is the main function and selling point of your app and is the first/only time it's visible, and it's kind of tiny.

- Cleanup the available styles example a bit -- it seems like you're showing every possible style available which when placed all together next to each other looks downright busy. I would pick maybe 3 or 4 icons that showcase the important variations available (size, cell-margin, color variation, etc.) and showcase only those, maybe with alice/bob style examples to show what they would look like in the flow of a conversation versus directly next to each other.

Configure page:

- Change the phrase "New users receive a free credit to evaluate the site" to something like "Try the service out for free" or "Evaluate the service for free" Explaining the whole credit thing on the sign-up page is way too much for someone just looking to test the waters in my opinion.

- Simplify or better organize the small print section, maybe separate out into sub-sections: explanation of how billing works, what you can expect from particl as a service, etc. At this stage in the signup process, you haven't necessarily sold the customer yet, don't lose them with scary large blocks of confusing text, especially if it's unnecessary. I'd either make it digestible or move it to a more appropriate section of the site and link to it.

General ideas for the business model -- I frankly don't see people footing a monthly bill for -just- visually attractive default user icons. I think for this to work, you have to add something else into the mix, here's what I've thought of:

- Solve the color-blind / accessibility issue and highlight that feature

- Offer a turnkey service for site owners to drop in to their own server, maybe even a complete commenting solution if possible.

- Offer a hosted complete commenting solution similar to disqus but with a premium and minimalist design.

- Offer tiers of service based on number of registered users, so sites start out with your service because it's free, and stick with it because it works, it's already in place, has good design, and is affordable.

- This is a bit hokie, but maybe offer a way to hash something more meaningful than a username, like say have a "personality quiz" that generates a badge for you based on your answers to questions.

- Have the user icons form a photo mosaic of something - maybe the site's logo?. I realize this would be difficult due to the simplistic color palette most logos have, but you might be able to come up with something
for this.

- Sell directly to the avatar-holder. I think there is a bit of cognitive dissonance between people who won't upload a photo to their account where they feel obligated to the community to put something there and want to customize their online persona, but don't want to reveal their identity to the internet. I think you could capitalize on this by offering a way for people to assuage their "guilt" over not contributing by maybe offering a service where you could donate to a cause, and in exchange get an exclusive avatar that has to do with the cause they've contributed. This would let people 1) feel less guilty about not "joining" in on the community 2) make their online interactions more personalized safely 3) spread awareness for a cause they care about 4) give those who care about it a little badge of honor. Maybe combine this idea with the mosaic idea and let people have a "piece" of whatever image represents whatever charity.