Private labels in the wine industry are a huge—and growing—part of the wine industry. Related questions have been on the Paper 4 exam the past two years in a row, reflecting this trend.
Interestingly, one thing that hasn't really been noted in this discussion is the rise of sommelier-branded wines, at least in the US.
While, as Jonathan mentioned, many restaurants dabble with private label wines, that segment of the business is a tiny, tiny drop in the bucket compared to the volume of brands like Kirkland from Costco, California Roots from Target, and of course, we can't forget the flagship wine from Trader Joe's: Two Buck Chuck!! In the UK, all the major grocery retailers (Waitrose, Tesco, Lidl, etc.) have their own branded wine as well. I answered this question, and I didn't even go beyond large retailers, though reading the comments above, I think you certainly could cast a passing glance at other types of less common private label scenarios, such as wine clubs, subscription services and restaurants.
A few other thoughts... I would definitely mention the consumer, as they are the last point in the chain. Are private labels good for them? On one hand, quality wine (i.e. wine that is typical of variety and place, as well as free of flaws) has never been cheaper for the consumer. On the other hand, these labels might be placing a lot of pressure on independent retailers, as they can't compete on price, which may cause a lack of product diversity in the marketplace for consumers down the road, as retailers close or condense.
Which leads me to my next observation: I would also distinguish not only between producer, distributor and retailer, but also big vs. small in each category. Private labels are often a boon for big retailers, but a total bust for small retailers for the reasons outlined above. Likewise, only large wineries can supply big accounts -- what about smaller wineries in regions with an excess of wine?
And lastly, only somewhat related, I bought the $29.95 bottle of Kirkland NV Champagne a few months ago, and it was actually very drinkable -- to be honest, better that a lot of big production NV Champagnes! I would definitely drink that over a lot of more expensive wine. Not sure if that makes me a winner or a loser...
Thanks Sarah Bray. We've ensured that our co-branded wines throughout our restaurants have enough of a price discrepancy from the other wines that specific winery might produce to prevent competition within the programs. Some major players in the DTC market include VinoMofo and No Bad Pair Days here in Australia (they really put packaging over quality), but even when looking at something like McClintic's Viticole, he's co-branded with Pax for a special cuvee. It's become a way for these online retailers to separate themselves by having something unique to them that might create an added sense of value.
One thought for out-of-US example is Champagne cooperatives, and of course examples from sparkling and fortified are always important on exams. Castelnau is one Champagne cooperative that does a lot of private labels, in the UK and elsewhere, including Scandinavian countries (sorry, I don't know more than this about the topic as it relates to Scandinavia).
Here is article with the following quote: www.thedrinksbusiness.com/.../
"While the Castelnau brand is only visible in the on-trade, the CRVC co-operative makes wines from grapes grown by its 775 growers, with many sold under their own labels, or as private labels for the likes of Waitrose and Marks and Spencer, which are nevertheless at the higher end of UK supermarket spectrum."
An obvious advantage is that Champagne is a brand in and of itself, but at lower price point that the famous houses, and as Rachel mentioned below, Kirkland example quite drinkable.