This oil is the same no matter who sells it to you for whatever price or shipping. Use this stuff, no other oils or additives, just straight up. I wouldn't stake my reputation to very many products, but I will for this one due to my experiences with it.
Tightest seating and best fitting you can get out of small engines that are designed to break in all loose and sloppy for longevity and stupid abuse. Just do like Denny said and run at varying rpm, just start out at an idle for a few minutes and increase rpm gradually (lipping of the cylinder walls can break rings) all the way to max rpm.
If you want more after hotrodding a motor, use this stuff and keep on using it at every oil change. Uh-oh, argument storm coming from everyone about the continued use of a break-in oil, zinc is for sunburns, etc. ............
Amazon.com: Royal Purple 11487 Engine Break-In Oil, 1 Quart : Automotive