Simply because they are not relying on bitcoins as theirbpromary source of income because at that time bitcoins is really not an investment and theybare just a digital money so peoplenare getting curious andnthey buy it and then they realize that you cannot buy anything with it becase there are no stores yet that are accepting it in that time. And then they are just holding it until it comes to the point that the bitcoins price rise up and they are just a lucky guys who have a chance to buy bitcoins in that time