fine if you don't get spooled, but then again so is a piece of electrical tape... i use a uni knot. it's a lot stronger than this. wrap 2x around the spool and create the uni knot down the line and cinch down fully away from the spool before you cinch it down.
I wouldn't call this the right way. TWo big knots in one spot on your spool causes a high spot in your spool which can affect casting. I just use a small overhand knot.