I think you should definitely consider offering multisig escrow because nowadays escrows are doing a hella lot of runners and you have the potential to start something great here. Multisig means that there is no opportunity for you to scam, unless the people taking part agree to give you a private key...
Dark net markets already do that and it is a lot safer for the people trading as well.
Or you are both the seller and the escrow. Rest assured, I won't even think about trying that, doesn't make sense to me.
I definitely offer Multisig escrow even though I don't explicitly say so.
The main use of Multisig is probably for the speedier transaction since it does not require the escrow to sign the transaction if everything goes fine. I would like to ask you, how many people know how to get their public key and how many people know how to sign a multisig transaction?*
*That's why I am not making it mandatory. The user can choose between using multisig or trusting me fully. Will make changes to my thread post if there is a significant demand, not so for now.