Guess most of you use the search window just to find a file, and then add it to the download window and stop searching. But I found out that in order to download the file faster (or in other words to get more sources in a shorter amount of time) it's better to:
1) search for a file until kazaa shows at least 100 sources in the search window BEFORE adding it to the download list
2) continue searching for this file even AFTER you added the file, search the entire time until the download is finished.
Here are my experiences: I found a file and added it immediately to the download window. looked up the file in the kdat programme and it shows that the file had 18 sources. Although I am using several download accelerators which execute the "search for more sources" command every couple of seconds, the number of sources stayed the same - after 5 hours! sometimes it even goes down! but after I started searching for this file in the search window of kazaa, the number of sources started to climb.
I tried with many different files, audio and video, specifically those that have very few sources and it always helped to boost the downloads.
I don't know what the reason for this is - maybe kazaa continues passing the sources from the search window to the download window even after a file download started. Or maybe the incease of sources is due to the fact that because of aggressive searches most supernodes kick you, which means you "come around" more, jumping or rather being jumped from supernode to supernode, which results in kazaa's finding more sources.
Of course, you have to be aware that this has a very negative impact on the network, but I have faith in the stability of the fasttrack network and don't think it will kill it.