> They all allow sharing pretty much the same (some content, whether it is text or photos) yet they are each hailed as the next big thing and the best thing since sliced bread
I think the difference is that with each iteration it became easier for the end-user to publish/share something. With GeoCities, they removed the need for a user to figure out hosting, running a server and purchasing a domain name (very expensive at the time). However, with GeoCities, you still needed to know how to write HTML/CSS/JS and use FTP. MySpace took it a step further from that point and did most of the HTML/CSS leg work but allowed for some minor alterations. Facebook took it even further and basically said, "we'll do all the leg work for you, all you need to do is type in a thought or upload a picture."
I think the difference is that with each iteration it became easier for the end-user to publish/share something. With GeoCities, they removed the need for a user to figure out hosting, running a server and purchasing a domain name (very expensive at the time). However, with GeoCities, you still needed to know how to write HTML/CSS/JS and use FTP. MySpace took it a step further from that point and did most of the HTML/CSS leg work but allowed for some minor alterations. Facebook took it even further and basically said, "we'll do all the leg work for you, all you need to do is type in a thought or upload a picture."