Many sites like these (skybtc as an example) have turned into a scam very quickly and end up not paying but really I have to ask, are these sites even worth your time/investment even if they do pay?

I know it's a faucet, and all faucets require a lot of manual labour just to make a little bit of btc, but you have to invest 0.1 btc (fair amount) to be able to get the over 300 satoshi a minute mark. And every time you invest, no matter what, in order to be able to make profit and not lose your earnings, you must always be ready to collect when the maximum is hit. That means checking it regularly, not to mention it could just shut down at any point. I think that using a faucet rotator would probably be a better way to make a few extra dollars as it requires no investment and if the faucets shut down you don't lose anything.

Plus if you're looking to get 0.001 btc in a day, there are so many pop up faucets around now that you can get in about 30 minutes.

So really, if you have no job and nothing to do all day and are ready to collect your earnings 24/7 but risk losing $40 ish dollars then go and invest but really I'd spend that time getting a job you can earn a lot more faster without risk