This first video (out of two) illustrates how we can segment "by needs" as marketing is mainly about catering to needs. Not how many people watch this video, but "Why" do you watch the video - what are your needs to do so?
The second video (out of two) shows how we can segment our customer-base by loyaly (Data-base Marketing) and includes the understanding that there are several levels of segmenting the demand as the person who buys the product is unnecessarily the one who pays for it nor the one who consumes it.