In a recent interview, the project director for Assassin's Creed II said that the first Assassin's Creed has sold 9 million copies. NINE MILLION COPIES!!  
 May I remind you that this was a new IP launched at the same period of time as Call of Duty 4 and Halo 3. The critical response wasn't that amazing either. What made Assassin's Creed so special? So mainstream?

Aw man, I hated Assassin's Creed... 
 
EDIT: Two very different posts in a row. 
 

@trophyhunter

" I really liked assassin's creed "

   

" I hated assasin's creed.  This is getting off-topic. "

I really liked assassin's creed

I hated assasin's creed.
 
This is getting off-topic.

People must have liked the concept of it, and Ubisoft did alot of commercials for it like crazy, I really liked that game so Im glad it sold so well

It had a pretty stellar ad campaign in addition to a female figurehead which means awkward nerds did half the publicity for them. That's what it comes down to. Left 4 Dead is the only game I've seen marketed nearly as thoroughly, or maybe Halo.

Great idea poorly implemented. It was essentially a tech demo extended into a game.

well I liked it and so did at least half of that 9 million did too

I have no idea why people like it so much. It's repetetive and boring.

" I really liked assassin's creed "

" @trophyhunter said:

" I really liked assassin's creed "

me too.  For such a charming game set in the past with all its thrill and shit, i didnt even NOTICE that it was repetitive.. i fucking loved it and used to wake up at 4 a.m. so i can run in Altair's shoes for a coupla hours before school. "

It also received a price cut fairly quick iirc.

Triple platform release, ton of hype behind the new IP before it came out that pushed people past reviews, and a lot of word-of-mouth saying it was awesome.

" Yup, they had a pretty huge marketing budget but a lot of games do. Mirror's Edge did commercials like crazy too, and they were pretty kick-ass commercials, but Mirror's Edge flopped. "

Yep, this is often overlooked.  This is why I keep saying it deserves to be mentioned in the same breath as MW2 and ODST when talking about the 'big releases' this holiday.
 
Why did it sell so many?  It looked unique (ie. not another game about cars or space marines) and the advertising for AC was absolutely incredible.  Hands down the greatest advertising effort for any game, imo.  The TV ads here in the UK ran for ages and they looked stunning.  It helped that the game played a lot like how it was portrayed in the ads too.
 
For me, it was these ads (assuming they ran them worldwide) that probably made the difference between it being a 4/5m game and an 8/9m game.  I bet a ton of people that had consoles gathering dust went out and bought AC on the strength of the advertising.
 
They could come close again with AC2 if they get the advertising right.

It was the marketing, shiny graphics, and the price cut (that's when I bought it).

" well I liked it and so did at least half of that 9 million did too "

" @Ahmad_Metallic said:

" @trophyhunter said:

" I really liked assassin's creed "

me too.  For such a charming game set in the past with all its thrill and shit, i didnt even NOTICE that it was repetitive.. i fucking loved it and used to wake up at 4 a.m. so i can run in Altair's shoes for a coupla hours before school. "

I played through it twice because climbing and running was fucking fun I really liked the story and it was a very pretty game "

" I have no idea why people like it so much. It's repetetive and boring. "

Apart from the repetition it was great. Great visuals, controls were good. Story too. 
 
9 million is surprising but then makes sense for this game.

I am rather surprised about this actually. I didn't really see the appeal, but my dad loved it. So much so actually, that he rebought it recently. 

I got my Xbox 360 last year and finally got to play Assassin's Creed this year. So far, It's been my favorite game I've played on my 360. Assassin's Creed 2 is day one buy for me.

With the best will in the world, Mirror's Edge was a game about running around; the advertising made it look like a game about running around.  
 
AC was about chopping dudes up with swords and stabbing them in the throat with a hidden blade; the ads nailed it.  Also, Massive Attack. 
 
 

" It was great, and technically impressive, the repition sucked, but still, it was worth it. "

Because it deserved to.

The repetition was lazy in parts, like when you hear people spouting out the same lines over and over. Sorry but that kills the immersion for me, and the cities were essentially the same except for a few minor visual changes. It's ok to have repetition but when you over do it, it makes you realize its just a game again.

It's all down to marketing. Personally I thought it was no better than Mirrors Edge... and that didn't do that well sales wise at all.

If you don't think what you repeat in AC is fun, fair enough. But it's not a valid knock against a video game to say "the same elements and mechanics are used throughout the whole game!". There is not a respectable video game in the world that doesn't work that way. And every game I've seen sell over 5 million copies ... that's right: They're all repetitive! 
 
Please complain better. It's getting repetitive.

 
Assassin Creed's combat:  A+ 
Other pars of the game: D- 

its like gta but medieval man! anyways thats what suckered me into buying it

The combination of heavy advertising and word of mouth is why Assassin's Creed sold like gangbusters.
 
And yeah, aside from all the repetition (which was the game's only major flaw) I really enjoyed AC, and will totally buy AC2.

i loved the game. But thats not revelant.
 
It sold because of an excellent hype campaign. I put a lot of credit to one of the early trailers, which made it look badass. I think it sold pretty well among casualish gamers for the apparent  awesomeness of doing a running jump on a dude and shanking him.

Just because lots of people bought it, doesn't mean they liked it. They were tricked.

Because it had a huge amount of hype when it was released and it's not a bad game aside from the repetition.

Everyone thought it was going to be the next great thing and it got marketed to hell, that's how.

First, many people lambast it for repetition, but it was a wonderful game with great visuals and above all, it was one of the most immersive games I've ever played. 
 
Also, although the rush of good scores petered off later on, it was getting 90s and 100s left and right at launch, due partially to hype, and otherwise because it was, in fact, a rock solid title that wasn't a first-person-shooter, like everything else released that year (exaggeration I realise).

I liked Assassins Creed a lot. It was repetitive but I was repeating something I thought was fun so it didn't bother me. 
 
It probably sold well because it was so hyped.

" Just because lots of people bought it, doesn't mean they liked it. They were tricked. "

I thought assassin's creed was pretty rad. I didn't notice the repetitiveness of it that much, because really. YOU ARE AN ASSASSIN! It's your job to kill guys.

I wasn't a huge fan of assassins creed, but it was a pretty unique and different game, and the marketing campaign reflected that, so a tonne of people will have wanted to try it out and would have bought it. That's why it sold so many.

I enjoyed it mostly.