"I wonder sometimes, how did Zuck think that this site of his would get so popular even if MySpace was waay popular back then?
What made him keep doing things?"
My answer is simple, it's based on historical knowledge of what was happening (or not happening) in the space circa 2004. It also is based on what had happened in the critical 5 years prior to 2004 that enabled the shift to a new type of social networking to be possible.
My first answer was:"Novelty, what is scarce has inherent value....doesn't matter what it is. Find a piece of 20,000 year old fossilized human shit (coprolite) and you'll understand what I mean."
To elaborate, there was nothing new concept wise about what Zuckerberg was doing....what was new was the technology he was using to do it. Almost every feature we have here on FB we had in some form on AOL. The differences were the lack of ubiquitous web accessible real time feeding elements which were made possible only with the invention of the XmlHTTPRequest object by MICROSOFT in 2001 to use in their OWS product (Outlook Web Access). The features of the object were quickly modeled into a version for non IE browsers and using it enabled background updates to the HTML DOM (document object model) which is an in memory tree of all the element nodes in a web page. Using XmlHTTpRequest calls (which are asynchronous) one can both make background calls to external resources on a page and based on the returns of those calls dynamically update the page elements, this allows the updating of pages without actual refreshes being manually performed by the user...making feeds (like this one) far more useful. Organizing content elements around a set of "friends" is something AOL was doing way back (95?) when on their service with their (then) innovative approach to IM. However, because their technology was silo-ed in two important ways that web 2.0 social networks were not (it was siloed in hardware because the users were all dial up and it was siloed in web technology because it was before XmlHttpRequest object was invented) it was at significant *scale* disadvantage to what came later once broadband penetration seriously started to pick up as telecoms laid fiber lines with abandon into the ground (which would soon be at over supply as ways to multiply bandwidth (DWDM multiplexing) became cost effective). Increased scale meant a much more efficient access to large swathes of people via any connection medium to the web and also meant the players could provide services with a much reduced technological load than older services like AOL...which required compiled software be installed on every computer using it.
So after the .com 1.0 era bubble burst in 2000/2001...new players started looking at the space (now with broadband penetration rapidly increasing) and said hey we can do that AOL social stuff but do it without any application to install, without any restrictions on access beyond a web browser that supports web 2.0 technologies...boom! Thus came Friendster, thus came Myspace, thus came Facebook...thus came Friendfeed...etc. Again ...in those early days...novelty and inherent scalability of the approach made those players inherently valuable ...just as today, consolidation took nearly 4 years and Facebook ended up winning the game despite early leads by MySpace...which failed to socialize their offering as quickly as Facebook did (the feed being key in my view).
Well....here we are.