Once the conversion is initiated, after 7 days you receive $1 worth of Steem that can be sold on any market for ~$1 worth of BTC or some other unit.
There is a fallacy in this case as well. Because, what we get is median of SBD value in terms of Steem for 7 days, which can be lower, higher or equal to 1 USD equivalent of Steem in other market. The point I am trying to make here is, though Steem Dollar is being promoted as stable value holding pegged to USD, in reality it is not working as expected. So far the spread is small. But, as Steem trading increases, this spread will increase more & more destroying the stable value property of SBD.