Both looked very much the same, but the comparison ends there. Ceefax implemented “links” as references to page numbers that the user would type on their TV remote. Minitel had a more complex linking structure, programmatically specified, with no URLs or ways to link to other “sites”.
What’s particularly interesting, looking back at Minitel, is the fact that it had something the Web never had: a payment system. Services could charge access to their content, proportional to the time you spent. The user would pay through their phone bill and France Télécom would give some of that payment back to the service.
Whether it’s a good thing that the Web never had an integrated billing mechanism is debatable. Imagine the outcry if ISPs started charging for access to some websites by the minute. However, it can be argued that it’s not because app stores have pay-for content that there’s no good free content, and that a billing system would make it possible for many small entrepreneurs to quickly earn funds to scale up their project and continue innovating. Right now, those entrepreneurs turn to apps precisely because they provide an easy way to get paid for the service they design.
It will be interesting when Google and Mozilla release their web app platforms with integrated billing systems. We may end up with the best of both worlds: the general web can remain an open platform giving the opportunity to tinker and hack, while web apps will offer the possibility of business models that will encourage innovation.