I find it amusing that he bothered to mention using char instead of varchar, but never mentioned that using nvarchar, or nchar, effectively doubles how much space is being used for that column.

Also, using char is only ideal when you know you have a consistent data length, otherwise you're throwing bytes into the wind again by not using varchar (which only takes up as much space as the data being stored, so if you have varchar(100) but only using 10 characters, only 12 [length of string + 2] bytes is used). if i had a char column and only use 10 spaces, the datatype dictates that the end have spaces, thus forcing it to 100 bytes.