The key parts of text on this poster would firstly be the name of the film 'Skyfall' and secondly and very importantly the 007 located under the title. As the bond films have been very popular and gathered a wide and loyal audience, the 007 would generate a lot of interest in the poster. As many Bond fans would see the 007 and automatically have an interest in the poster. The 007 is also the only part of the poster that isn't in black and white, meaning the audience would be drawn to this as a point of importance.
The main character of this poster is Daniel Craig who is widely recognised as James Bond by the audience and fans from his previous parts in Casino Royal, meaning the fans of the genre would recognise the actor and relate him to other Bond films. The same could be said for the older Aston Martin would could mean the poster is trying to relate more with the older set of James Bond fans.
Also the fact that Daniel Craig is holding a weapon which links to the action genre that the film has followed. this could also mean that audiences that havent watched many James Bond films would be attracted to the film as being part of the action genre. Also the postitioning of the main character in the poster looks as though be has either had a hard decision to make or in the process of making one. Meaning that there could be something like a plot twist in the film, making the audience eager to watch the entier film apon relese.
Also another important aspect or the poster is the backdrop of London showing the this is the main point that the film is set, drawing in an British audience, However the fact the London is a very cultural and well known city it would also draw in audiences from around the world.