Pieroth is a family owned and run business which can be traced back to Burg Layer Germany almost 340 years ago. They own all of the vineyards they supply from and only deal in 'Fine' wines. Somebody has mentioned in a previous comment that they are no better than supermarket wines, this could not be further from the truth. Supermarket wines are mass produced and are full of artificial chemicals, sugars, additives and preservatives, where as, fine have none of these.
Pieroth started the home wine tasting approximately 50 years ago as a way of expanding an already very successful company.
There is no catch with these tastings. It is true that the ultimate goal is to sell to us, the consumer, but they have a solid reputation.
I have personally been dealing with them for some time now, as my Father did before me and I have never, to this date, had a bad experience with them. The are a little more expensive than supermarket wines but you are paying for quality not quantity.