Yeah, the thing about dtube is, they take 25% of the revenue and use 2.5% to pay for storage. (That is 10% of the revenue that is forked to them). To make it available longer, youll have to either run your own ipfs node and provide the videos or rent some space yourself. At that point though, you may as well share the video directly via steemit instead of dtube, the only reason for using dtube at that point could be that you are not well known enough and hope your content is found on dtube. It can be found on steemit as well, of course (or any other plattform showing your posts from the blockchain for that matter) but dtube being just videos may give you greater chances there.