First, let it be known that a few posters had it right when they said
1 - Sometimes there are "exclusive" deals that prevent other companies from sponsoring events and tours (doesn't mean others aren't trying), and
2 - There is a lot that goes on behind closed doors that the general public isn't aware of that does affect sponsorship and cloth choices
With that being said, I can answer some questions about Milliken Super Pro. It has shown to play more consistent over time than other brands. Most cloth with a high nylon content will show wear, some more than others depending on their weight, however the true test of performance is consistency. When someone can go from table to table and know the speed will be the same, that player can have more confidence in his shot-making ability. When a pro or top level amateur shows up and an event and knows that the speed of the cloth will be the same on day 1 as day 5, and the cloth doesn't skid or allows balls to slip and slide, they are better able to produce a championship performance. This is why Milliken Super Pro is quickly becoming a preferred cloth in Europe, Asia, Australia, and the Middle East. America is behind the curve on their ability to judge a new cloth without bias.
When it comes to sponsorship, I guess many folks here are unaware that Milliken has been a sponsor of regional tours such as the Tri-State tour, Blaze tour, BAAT, as well as independent events such as the Generation Pool Championships, the Canadian Championships, and well as numerous other smaller independent events.
The real testament, in my opinion, are the rooms that have put Milliken Super Pro on, and continue to do so, even when given the option of recovering with less expensive brands. Also, the table mechanics across the country who have come to recommend Milliken to their customers, based on their experiences with the cloth.
I sell Milliken, and when I see a thread like this, I feel compelled to let folks know more about the cloth so that they can be informed. Pardon the "schilling" for a brand I sell, however I feel if I don't let folks know some of this information, they may not hear it otherwise.