If you roll over the different options 'post, share and chat' it gives you some more info about what we are trying to do. We will look to make it clearer.
There is a return to neetly home in the top right hand corner (after you have clicked sample network) - again can make this clearer.
I also had no idea what it was meant to do from the tagline - at least say social network or something. It was not at all obvious that you could roll over those pictures - they need to look more clickable. Like others on this thread, I didn't spot the Sample Network link at all until it was pointed out.
I will often watch a screencasts on the front page of an unfamiliar website if I can't figure out what it does - maybe that is worth trying?
There is a return to neetly home in the top right hand corner (after you have clicked sample network) - again can make this clearer.