Europe - Languages!
Europe's retail situation is not really comparable to the US for a number of reasons.
It's more fragmented because historically-speaking, the EU has only been a single market for a relatively short time compared to the United States, each country is still a country. They're not states within a union and, perhaps more significantly, they also tend to speak different languages.
There are a number of huge retailers with presence in most EU markets, but the brands they carry are representative of the markets they operate in.
You also have old brands that have had billions spent on them over the decades, ditching those and replacing them with pan-EU brands has proved very problematic when it has been done in the past.
Some brands simply do not work very well across multiple languages. For example, Persil means Parsley in French so it hasn't ever been used as a main-stream detergent brand in French speaking markets.
Or, take a product with a word like "Mist" in it, which means manure in German.
So, something like New Persil Mist could cause you a problem in multiple markets !!
There have been utter disasters in marketing too over the years where someone's gotten this horribly wrong and ended up naming a product something that turns out to be rude.
I have a degree in marketing and I spent a lot of time analyzing this stuff
Europe has produced enormous consumer products companies like for example, Unilver and Nestlé are the 2nd and 3rd largest in the world. Others include Henkel, Reckitt and Benckiser, Biersdorf (Nivia), L'Oriel, etc etc etc and there are many other huge European organisations in that sector too as well as the likes of US corporations like P&G, Mars etc which have European operations that are entirely independent of their US operations with totally different product ranges.
In Europe these companies achieve economies of scale, but they do it differently to their counterparts in the United States where you can operate a single US-wide marketing campaign.
Over here you would generally find that companies will concentrate their manufacturing facilities into one or several huge centres and make all of a particular type of product at that location. Transportation issues are not really a big deal in terms of overall costs. Yes transport's a bit pricer than the US, but Europe also has a pan-European motorway network, pan European high-speed freight train networks, etc etc. Quite comparable to the US in that regard. Hundreds of billions of Euro worth of goods are shipped across Europe every day by road (mostly) but also by rail.
It makes no more sense to do regional manufacturing in Europe than it does int he US. Although, regional packaging is sometimes done to allow for local branding.
Where regional brands exist, you will generally find that companies produce the same base product with minor tweaks e.g. scents, or they just produce exactly the same product for all markets and only vary the packaging.
In many cases, for example Unilever products the same logos and packaging are used with multiple brands. The "heart brand" ice cream is the best example of this!
This means they also get economies of scale when it comes to advertising. The same advertising campaign (including TV ads) often gets used with different logos and minor tweaks and different voice overs in each market.
The situation with things like household products is actually quite straight forward as in general it's quite easy to market something like a detergent or a cleaning product across the entire EU once you get the localisation right for language.
However, food is another story entirely. Each market has different trends and slightly different food cultures. So, while some products like maybe candy, coffees, soft drinks etc will sell across multiple markets, you can find that more traditional regional products don't sell well outside their home markets.
So, with food products regional manufacturing is still pretty much the norm for many products.
You also find a number of massive European fast-moving consumer goods brands that operate across all or most markets e.g. L'Oriel, Nivia, Ambre Solair, Finish, Cif, P&G Europe's Ariel brand, Persil (in most markets), Omo, Surf.
Other product types like appliances, cars etc tend to operate on a purely pan-European basis. There are a couple of minor exceptions, but in general that's the way things have gone in other sectors.
Increasingly you're also seeing things like pan-European telecommunications operators operating with a single brand in most markets: Vodafone, Orange, T-Mobile, O2 etc although still without any integration of those markets!!
Basically in Europe you've got a lot of consolidation but, you still need a lot of local tweaking too to cope with different market requirements like language, technical specifications (e.g. plugs, which side of the car you put the steering wheel etc).
However, it's a single market and product regulations, safety standards, environmental standards or anything that could create an internal market barrier within the EU are regulated at an EU (quasi-federal) level, not a national level. So, basically once a product's approved for sale in the EU, it can be sold anywhere in the EU.