Let me examplify my ownself here in USA.
There is a parts shop called NAPA here - They stock Liqui Moly products - and about 90% of the stock remains collecting dust as only some "anokha" person comes in to order that product at full payment and then collect it later on as it has to come from their warehouse.
OTOH Their own line of engine oils which are basically repackaged valvoline products are being sold by the case/drum/tote everyday to almost all shapes and sizes of shops - their clients are usually govt contractors, school bus maintenance depots. truck stops, automotive repair shops etc and also retail counter for normal everyday people.
I also order their own product line (specially when they put in on sale). However For ATF and diesel oils I use Citgo oils which make some amazing quality stuff - and easily available at the industrial parts store which I order from. I also use Phillips 66 and Kendall oils (which are unheard of in Pakistan or anywhere outside of USA - they make Ford Motorcraft oil products). - Different oil depot.
TL DR
dont fall for fancy names unless you get empirical evidence of the oil's performance and the co. branding stands behind it.
I do order shell (sold as penzzoil here) when its on a discount - nothing much different.
The german brands are atleast twice as expensive and dont quite interest me or most people - if you are running an M series BMW and need the fancy 10W60 oil they require - you will have to buy the LM product - but otherwise their sales remain slim compared to the regular runners.
