It's just the same wolf inside a new sheeps clothing. Previously it was known as factoidz dot com.
I have many reasons not to like factoidz and its owner. And there were others who were also burnt with similar experiences.
If you looking at stretching out and publishing elsewhere (it's always good to not have all your eggs in one basket) then there are plenty of opportunities, but I recommend avoiding Knoji. In the very least do some homework and be sure to look up information on factoidz before you make a decision.
Factoidz returns nearly 100k hits when one does a Factoidz+Rip Off search. Reading the experiences of others....hundreds of others, should warn even the most slow brain that they will lose their copyright. And just because "Oh, I joined Factoidz 3 months ago and they have always paid me", (twice) doesn't mean they will pay you next month.
Furthr, be aware of shills, (i.e. the horrid Jerry Walch) who will denigrate any one who dares post a warning. This is because Walch makes money from the work of other writers who were dropped to member.