Yes, I quite understand that the demo video will not help me in any way. I just wanted to try the site and games before uploading real money there. To try the interface, etc. this is usually provided without problems. Therefore, I clarified.
It is good choice that you have decided to check the demo video before depositing real fund. I don't think it is necessary as you cant know anything about the betting site by checking demo videos. Hence if you think the site is okay (not scam) then you may deposit and if you found the fame you do not like then you may withdraw the fund.