When you are connected to Netsukuku, you get a very fast path (think ludicrous speed) to the devices that are located geographically near to you. Also, you get a connection where your upload capacity is as high as your download capacity. I put these couple of features together for reasons that will be clear when I get to the example.
This is absolutely not what you get with your Internet provider. You get a direct connection through your DSL line to the routers of your ISP, which are located usually quite far away from your house, and which become the first hop for any of your connections. Hence, no matter where the recipient of your message is located, the packets your computer send have to go all the way to your ISP first.
Second, your ISP usually gives to you a download capacity (which they incorrectly refer to as the speed of your connection) of 4 Mb/s and an upload capacity of 512 kb/s or less1.
As a result, interactive online applications suck. Pooor quality VoIP, slooow online games. Even web applications (gmail, facebook apps, ...) feel like they receive your input with sensible delay. We usually blame the servers, but it's not their fault often. You mostly feel this problem if you contemporarily send big data (e.g. post photo on facebook, use bittorrent, ...)
Within a Netsukuku network, instead, you are connected directly to one or more of your neighbors, which are located very near to you (e.g. within wifi range). You can also have a direct connection with a node far away. It's the software that always uses the path that has the shortest trip (in travel time) to go to the destination. You never go forth and back in order to send a message to someone very near.
Further, the links that you have got are owned by you and your neighbor, and no one else puts a limit on link capacity, either direction. When carefully crafted, nowadays a wireless link can get something like 100 Mb/s.
So, one can set up a game server somewhere and invite his friend to play online with unprecedented speed. Or, you can have a video-chat with your neighbors with near HD quality. Or, you can remote control your home PC from the office and viceversa. The imagination is the limit. If you think about it, then you'll see that the majority of your needs are often located near to you, more so than your ISP is.
 Your ISP wants you to just download things. When you are uploading you become a source of problems for them. In fact that scarse upload capacity that they give to you is what is necessary for the download to work, because when you download a stream you also have to upload a few data to acknowledge the server.