The size of the Netscape cookies.txt files on my machine range from 1 to 4k bytes. The cookies take up less than the minimum size allocable. Certainly not large enough to run me out of space. On the other hand, Microsoft designed IE to create a separate file for each cookie. If your cluster size is 32K, then they take up twice as much room.
Cookies can be beneficial.
The cookie set in these sites allows you to go from one product to the other, while remembering what you have on you shopping list. Cookies can hold preferences for you at web sites. This can be beneficial if you like to use one search engine repeatedly. A cookie set at a web site may prevent you from seeing the same ads every time you visit. In fact, depending on what you search for, particular ads may be presented.