Our friends at Wetpaint make it really easy for anyone to create a free website about anything, share it with other people and even include other content contributors. Wetpaint is most often classified as a wiki company, but when reduced to first principles – and from a user-facing perspective – Wetpaint is about letting people get content on to the web easily.

At mainstream scale, product category distinctions disappear, and wikis like Wetpaint stop competing primarily with other wikis, but with any other company with scale and traction that lets regular people put content on the web easily.

Beyond wikis, easy web page creators like Google Pages, and Weebly approach the same basic use-case from the web-design direction.

A third group can be loosely termed people powered search result or topic pages, and run the gamut from the venerable About.com to more recently Seth Godin’s Squidoo and lately, Jason Calacanis’s Mahalo.

As products in all of these categories mature, they have begun to converge from a feature set perspective. Page creator sites by fleshing out ‘invite friends’ features. Topic sites like Mahalo are adding wiki features. And wikis like Wetpaint continue to beef up their visual, WYSIWYG page creator features.

Will one approach win out, or are all of these companies solving essentially the same end-user problems? All of these companies depend heavily on SEO to drive traffic and adoption – and category representatives Wetpaint, Mahalo, and Weebly have been growing nearly in lock-step to date.

Blog platforms like WordPress or Typepad obviously also make it easy to put content on the web – but these already have much larger scale – so I am not using them for comparison. White-label social networks – and I am mainly speaking about Ning here – are approaching from another position – but Ning is different enough that it probably warrants discussion in another post.