Retroshare has awful usability. I am a smart person (yeah yeah), a programmer and a hacker and I ended up with two and a half accounts. Between two machines in the same local network it transferred files with 15 Kilobytes/s. I had to find random posts online to figure out if a blue non-descript icon meant I was sharing files with the world or no-one or if it was the green icon or something else. It looked so promising but turned out unusable.

AFAIK every successful IM platform out there is successful because of this effect. Users push their peers to adopt the new IM because without their friends it's not very useful to them.

Of course there should be a good reason for the "seed" users to get on the new platform in the first place.

apparently there is no reason for them.

even with PRISM and others, people are too lazy for that.

Educate them.

the most difficult task in the whole world. and they have to be excited... but where I live, nobody gives a sh.t what NSA does with all the private data.