This year I've been involved with two of the main sessions at the upcoming IGF in Guadalajara. Being behind the scenes gives you a bit of an insight into why these always seem to end up being so disappointing.
First, the IGF allocates no budget for them. None. I mean, you do of course get the translation, and some assistance from the Secretariat with basic logistics, but say for example that you want to retain a professional moderator, such as most conferences of this size have—then you're paying for that out of your own pocket, or more often, doing it yourself. At last year's Dynamic Coalitions main session, I was even personally buying stationery for use in the session.
Second, they have to be organized by IGF MAG members, even if they have no connection to the topic of the main session, and no knowledge or experience to qualify them for doing so. There is no obvious reason why this should be so. Sure, it makes some sense that the MAG should approve any main session topic. But why should they also be responsible for seeing it through? MAG members are not chosen for their subject matter expertise, and this explains a lot about the low quality of most main sessions.
Third, the appointment of speakers to the main session is based on political patronage, rather than merit. The power blocs within the MAG can block those that they don't like, or hold a session's approval hostage until their favoured candidates are appointed to speak. Regional, gender and stakeholder group balance are also prioritized over knowledge and experience. This results in panels that are large, weak, and lacking any outlying perspectives.
The way in which main sessions are organized needs to be thoroughly revamped if they are to start to attract more interest at IGF meetings, and a good start would be to divest the MAG of its responsibility for organizing them, and instead to outsource this role to independent experts, with appropriate resourcing to allow the sessions to be staged to a professional standard.