Is the Dunkin vs. Starbucks study legitimate?

I went to the site and there are virtually no details over how many preferred Dunkin Vs. Starbucks. It just said they surveyed 475 adults or so. There were never any details on exactly how many preferred Dunkin over how many preferred Starbucks. I think its totally biased. I tried them both and I can say Starbucks is better. It just bots Dunkin beat Starbucks. Was it by a landslide or by a few votes. It's things like these they didn't want to get into.