I downloaded the new uTorrent (µTorrent 3.2.1) client and was annoyed by this new banner for featured torrents to download. I looked up and down in the preference and after some extensive searching was able to find out how.

by going to Preferences, and then Advanced. In the filter, type in “sponsored”. This will give you “sponsored_torrent_offer_enabled“. Set that to false, click OK, exit uTorrent and start it again.