I agree with Eduardo porter on this, people post loads of content on the above mentioned sites and not get paid rather they loose their data while doing so, but I think steemit has been on the right track from day one which is post quality, creative and original content and earn. So using your data to post on steemit is great because you are surely going to be paid for doing so. Great and educative topic you raised at sndbox, I call this an eye opener.