Helping a FOSS project tip over the technology adoption curve

When does a new FOSS project take-off, become really popular and move in the main stream?
What are the necessary pre-conditions or attributes of the project that allow it to tip-over the adoption curve?
I will hazard a guess at a few relevant attributes:

• Useful: the project must do something useful. Either it is a better or novel solution to a known problem or it is a new solution to a new problem. Whatever the case, it must help solve some problem. This is a necessary, if not obvious, pre-condition.



• Honest: honesty is important because it builds trust. Trust is important because it is the basis for an on-going relationship and the basis for a technology adoption decision. Honesty is easy to achieve. It is about simply ensuring that the project 'does what it says on the tin'. That it is fit for the purpose for which it is intended. If the project is a first step in the direction of a solution with a bunch of explicitly identified known-limitations, that is ok also. The key point is that there is no world domination marketing blurb, no spin, no claims about un-tested or un-implemented features, no ifs or buts etc.
  Honest revelation is important for two reasons. First, because it is the truth and because it forces identification and analysis of the current reality. Second, because you can be found out. The source is open and the truth is in the code. The type of people an early FOSS project needs to attract can and will read the source-code.
  If a FOSS project is honest, the users first impressions will be a valid reflection of the project. There can be no disappointment. If the intent is perceived as useful, the user can decide to adopt, track changes or get involved. In essence, the project stands solely on its 'usefulness' merits.



• Extensible: The architecture of participation is important. Successful projects get this right from the beginning. Outsiders are presented with clear opportunities to contribute to the project.