Viz’s SigIkki website isn’t just an experiment in manga for mature readers. Going to the site does more than let you read some great manga. You, the reader, can make a difference in which manga will get published. Your clicks and reviews can make all the difference in the world for a title seeing print.
In Japan, the fate of a manga is decided not just by circulation, but also by what the readers say. Survey cards are checked and titles can live or die by what readers say in these. Viz has taken this idea and applied it to the web. The titles at SigIkki are not guaranteed to see a print edition unless enough people show interest through page views and reviews that readers can leave. While this is a good idea for a small market as these Ikki titles will attract, that also means that your favorite title manga get a print edition unless YOU do something.
Just like pre-ordering, this is putting your money were your mouth is, just without so much of the risk. Going to the site and reading chapters is easy, but if you really love a title, so much so that you want to see it in print, then put in a good word. The editors give a lot of weight to reviews and comments left for titles.
And, just because a title gets a future solicitation, as many of the SigIkki titles seem to have at Amazon, that’s not really a guarantee of publication. Ask Tokyopop about that.