Most notably quality control, and especially some sort of peer review, were missing from earlier web-systems. For example in forums, newsgroups and wiki's there is no good way of differentiating between quality contributions and problematic or even worthless ones. Many of these are completely open 'anarchies', where people with too much time on their hands (or worse, nutballs) determine or even pollute the conversations. While other forums and wiki's take the opposite extreme and are partially fenced off or sometimes completely closed and/or have unchecked admins as arbiters.
Wiki's have the additional problem that only one page with the same name can exist, causing problems when there are disagreements over what the contents of a page should be. This can either only be resolved by a decision in favor of one of the viewpoints, or the page has to be made longer and less clear cut by incorporating both views.
Forums and newsgroups rather have a contrary problem. On them, because of threads, older posts and discussions quickly fade from view, and are time after time - with intervals of some months, or less - repeated all over again. Here posts are replaced too quickly, and either there are no social rewards, or they are too small to attract and keep many, if not any, serious contributors.
LogiLogi bridges the seeming contractiction between openness and quality by having small texts that compete with eachother in a meritocratic democracy. The rating with differences in voting-power, coupled with simple filtering, maintains quality. And in as far as openness is not secured by allowing all authors a vote, it - and especially plurality - is by the fact that new peergroups can be created by anyone on LogiLogi, so there is room for a diversity of refreshing views and approaches.
Of course drawing users and authors to newly created peergroups will be hard, but that's only natural, as time and attention are scarce. In a sense peergroups within LogiLogi function like a market, in that individual actions (like writing and voting) lead to a better usage and distribution of attention - the scarce resource - on a collective scale. And just like the market, it limits opportunities for corruption and favouritism by aggregating over the small decisions of many different individuals.
Lastly, LogiLogi brings not just attention to ideas and to texts, but also to good authors. Especially as more people start using it, being highly ranked in a peergroup is hard and well earned: it really means something, not just in terms of quantity, but certainly also in terms of a proven quality of work. This - in addition to the interaction with other users - will make writing for LogiLogi more socially rewarding.