Agree with you that tecnical solutions exist, but then we are not the only one to use "proprietary social media". So its not bad using it. Everyone uses it, be it Jimmy or events like Wikimania. The primary intent is to reach out and in a simple way. Well as i mentioned before, If you want help out spreading the word by using free media, you are more than welcome.

Lets not also get paranoid about Free stuff, which case the conference needs to have a hotel which only uses Free stuff (right from bubble top water,everything is proprietary)  and so on. Lets get real, while we support free culture, we need not always be living for it.