You've probably noticed by now that last week, the very first trailer for James Cameron's up-until-last-week eagerly awaited mysterious $200m+ blockbuster Avatar appeared. Since that point, the trailer has been dissected in detail, and it's been reported that on the day of its launch, 4 million streams were logged at Apple's website. That might account for why the thing took quite so long to download, but it's nonetheless a very sizeable number.

What struck me about the release of the trailer, and the subsequent screenings of 15 minutes of footage from the film that took place to those able to nab a ticket in various locations around the world, is that Fox's marketing team seems to have bet the house on the past seven days. Earlier this year, Mark Pickavance penned a piece on this site where he argued that the secrecy surrounding Avatar was getting a little tiresome. I saw his point, but for once was quite enjoying the fact that every facet of a major motion picture wasn't been rammed down our throats, to the point where it felt that I'd seen 20 minutes of it before I walked into the cinema (I'm looking at you, Harry Potter).

Fox, however, clearly knew at some point that it had to let the cat out of the bag. And thus it seemed to be displaying a genuine confidence in its project by setting up the unprecedented programme of preview screenings last week. I can't remember a time before when a 15 minute segment of a major film was so widely screening four months ahead of release, and the assumption the people went in with was that James Cameron had come up with something genuinely spectacular. After all, you don't, as a rule, tend to let people see so much of your work so soon for no reason (and Fox, to its credit, has a proven track record of making decent hits out of films that aren't screening at all in advance - The Day The Earth Stood Still and The Happening being key examples). Given that much of the discussion about Avatar thus far has been about the technical side of things, here was the chance to see just what James Cameron had pulled out of the bag, and also an opportunity to see for the first time something of the film too.

Things, it might be fair to say, have not quite gone to plan.

The release of the trailer was always going to, in retrospect, be a big moment for the film, especially given that so little was known about it. Yet people were on the film's side, and when the trailer went live, a mass stampede to Apple's trailer hosting website - the only place where it could be viewed properly - began. Troublesome links and long download times from Apple were the immediate obstacles, and we were bemused that the official home of the trailer also managed to declare that this was 'From The Director Of The "Titanic"', adding a word before the title of Cameron's last film that we don't recall being there when its name was being read out at the Oscars.

But back to Fox. Instantly, an army of sites such as ourselves began to link to the trailer, and there seemed to be a real enthusiasm to see it. This, surely, was just as much part of the plan, to get Internet tongues-a-wagging, so that they could effectively do much of the promotional work on Fox's behalf.

We can't speak for anyone else, but what we got for our troubles was a letter from Fox's director of intellectual property, accusing us of posting content that "infringes Fox's intellectual property rights". We were genuinely amazed. Given the weight of the job that Fox has on its hands to sell a big budget film this Christmas for which awareness amongst mainstream audiences has not been high (and won't be helped, we'd argue, by a poster that only has a blue figure on it and the name of the film), we suspected that Fox would engage with the web community in an effort to spread the word of the film. Instead, and we imagine that other sites received this too, we received a demanding letter that said, "I have a good faith belief that the use of the material on the website ... is not authorized by Fox, its agent, or the law."

Our crime? We linked to the Apple website hosting the Avatar trailer. Had we actually hosted a dodgy YouTube link of the Avatar trailer, then perhaps it would be understandable. But we didn't, and instead of checking our post, Fox has presumably done a sweep of Google Alerts, and sent out the legal hounds for what amounted to a website linking to its official trailer. Bizarre doesn't begin to cover it.

Then we come to those screenings. We've noted before on this site that Avatar is going to be a tough sell, one that's going to need to reclaim a lot of money for the studio despite arriving very late in the Christmas movie season (a week before Christmas isn't a lot of time to claw back money before the Oscar contenders trundle along). The material that Fox and James Cameron demonstrated in its 15-minute presentations therefore needed to be a firm smack out of the park, the kind of footage that you instantly ran to the pub/your mate's house/Twitter to tell the world about. But again, that's not what's happened, and when the substance of the Avatar film has come to light, it's proven far more divisive than Fox needs it to be for it to get people to think about prebooking their tickets right now.

If all had gone to plan, by now, Fox and James Cameron should be basking in the aftermath of a week that effectively launched Avatar into the world, and in theory, should have got people jumping up and down to see it. What's happened though is that far from snaring in a mainstream audience's interest, it seems to have thrown the once rock-solid enthusiast audience into doubt. Tickets that were all-but-sold this time last week aren't looking quite so firm now, and what Fox does over the next couple of months is going to be absolutely crucial to the film's success. Because the truth appears that the promotional campaign has not started as well as you suspect most would have hoped, and that gives Fox four months and counting to make Avatar the film this season that everyone wants to see.

For me, it's still the one movie I won't be missing this Christmas, and my ticket remains sold. And I'd wager that some of those wavering after the last week will still be joining me. Yet I'd hate to start guessing though how many people are standing behind me in the queue.

I still believe that James Cameron and Fox can pull this off, it's just I'd hate to be the ones tasked with making that happen.

• Review: 15 minutes of Avatar in 3D IMAX
• James Cameron's Avatar: the trailer is here
• The Avatar Trailer: Oh dear
• Avatar - has sci-fi truly found its Heaven's Gate?