I think they do, too. As I've mentioned before, for people with European cars, Castrol was the go to oil for a long time, simply out of availability. Once upon a time, all the Euro stuff from everyone was only in one litre bottles, which are expensive, of course. But, at least GC 0w-30 could be bought at every mom and pop automotive shop; if you wanted GC, it was everywhere. Wakefield doesn't play games when they market up here. If you're carrying Castrol, you're very likely to be carrying a healthy selection of it. They even have somehow convinced Walmart Canada to carry like three or four versions of CJ-4 15w-40 products.
At a local automotive shop, I can get Castrol 0w-30 A3/B4, 0w-40 A3/B4, 5w-40 A3/B4, 5w-30 A3/B4, and 5w-30 C3/dexos2. Let's see Shell Canada or Imperial Oil top that. For my personal cars, as I was growing up, I used a lot of GTX, for one, because it was always on sale, and two, I wanted to differentiate it from the taxi stash.
I don't use much Castrol stuff these days, but it is nice to know that if I want an A3/B4 lubricant, there is at least someone offering more than one choice and I don't need to go on a major expedition to find it, either.
People also shouldn't be too hard on Castrol for spending money on marketing. Yes, some of the marketing is stupid, but Mobil and Shell don't exactly have a shoestring budget when it comes to marketing, either. How many hundreds of millions does it cost Shell and Mobil annually to have big visibility on three Formula 1 teams, not to mention on tracks all over the world?