It's pretty non-obvious. I'd recommend making the text readable without mouseover if you want people to read it at all.

Consider users on touch devices, too. I'd generally avoid using hover effects, and if you must, keep them subtle and don't rely on them for usability.

There is no mouse-over in iPads and iPhones

* Sent from my iPad

My honest impression was that you must not be very good at what you do if you can make something as basic as reading your site so frustrating. Then when I came back here and read that you have to mouse over the text to read it, my first thought was "why would someone who advertises does iOS work make their site impossible to read on an iOS device?"

I did eventually go through and check out your 3 degrees of wikipedia app, and thought it was very impressive.

But people with tablets or Mobile phones won't be able to do that.