Using Merge to Update or Insert single row of data

Example of recent procedure I wrote to either update an existing row or insert a new row.
Table has the same structure as MembershipEmailFormat the table variable.

Found it easiest to create a table variable to be the source in the Using clause.  I realize that the main purpose of Merge statements really are merging muliple rows between two tables.  My use case is that I need to insert a new email address for a user or modify and existing email address.

CREATE PROCEDURE [dbo].[usp_user_merge_emailformat]
        @UserID UNIQUEIDENTIFIER,
        @Email varchar(256),
        @UseHTML bit
AS
BEGIN
    --SELECT @UserID='04EFF187-AEAC-408E-9FA8-284B31890FBD',
    --       @Email='gkindel@merge.com',
    --       @UseHTML=0
       
    DECLARE @temp TABLE
    (
            UserID UNIQUEIDENTIFIER,
            Email varchar(256),
            HtmlFormat bit
    )       

    INSERT INTO @temp(UserID,Email, HtmlFormat)
    Values(@UserID,@Email,@UseHTML)
           
    SELECT * FROM @temp    

    MERGE dbo.MembershipEmailFormat as t
    USING @temp AS s
    ON (t.UserID = s.UserID and t.Email = s.Email)
    WHEN MATCHED THEN UPDATE SET t.HtmlFormat = s.HtmlFormat
    WHEN NOT MATCHED THEN INSERT VALUES(s.UserID,s.Email,s.HtmlFormat);
END