It's been a while since I updated this, but a lot of stuff's been going on since then and I haven't had the time.
Long story short, I got "let go". At the end of April, I asked if my boss was happy to make my employment permanent, and he said he was; he'd get a contract drawn up and make everything official in a few days. About a week later, he said he'd been reading through Facebook's ToS and basically said there was a loophole which meant he could get away with his advertising campaign without violating it, but he said he would be the one doing it because he knew I had reservations about the whole thing. Fast forward a fortnight and I was ill; I told my boss I wasn't feeling great, so he said I should go home and rest. Next morning I head back into work and there's a new guy at my desk, boss looks surprised to see me, insisted that I go back home and rest. I didn't want to argue, so I left. A few hours later I get a call from the boss, asking me how I am; I tell him I think I'll be able to come in tomorrow, but he basically tells me not to bother. Apparently I'm not "enthusiastic enough" and they want someone who will give 110% at all times. Apparently I'd put him on the spot when I asked him if he wanted to make my employment permanent and he "hadn't been able to think it through properly". I call bullshit. He probably didn't like me being difficult over the whole Facebook/YouTube thing and decided to get rid of me while he still had the chance. Kinda not really surprised, to be honest.