Steam or many (if not all) games [platform] arent valid collateral since they can be reversed. As in regards to collateral, many would say that they would sell it but the point of collateral is something that can be secured by the lender that the borrower dont want to lose. Altcoin is a good example because say if you had enough put ethereum at the current price and during the term of your loan, it goes up in value, that can be a plus for you but the downside is if you default, you wont get your coins back so that extra value goes to the lender. Its like saying if you need a loan and have a car, you could go to a bank or a loan service and get a title loan against your car. Same with your house. If they go up in value and you default, your lenders get your car or house. So saying you would sell something if you had it doesnt mean much to anyone here. Most only do it as a last resort, especially when it come to altcoins.