Magazine front covers must represent the 'feel' of the genre(s) that they are about. Major differences can be seen from genre to genre, as they need to represent that genre and the people who are fans of that genre. For an example, I have collected three magazine covers from three different music genres.
1) MixMag
Mixmag is a music magazine aimed at fans of dance music.
The font is rounded and playful looking, suggesting a young, modern feel. The design and graphology has an emphasis on roundness and circles, possibly to emulate the circle of a record or CD. The inclusion of a piece of old music tech suggests that the magazine focuses on music technology. The clothes of the model and the background are fun and colourful, suggesting a younger audience. They are also quite feminine colours. The exposed chest of the model would suggest that the magazine is primarily aimed at men (although the soft graphology may also appeal to females).
These implications of the audience in just the images and graphology of the cover match up to what we would think the average person who listens to dance music is like: young, fun-loving males who are into technology.
2) KERRANG!
Kerrang magazine's target audience are fans of rock music.
The logo is in all capitals with an exclamation mark, with a scratched, smashed looking font. This immediately suggests destruction and violence, but in a music context it may be trying to emulate the rage and exhilaration of something like smashing a guitar. It also suggests loudness, and rock music is usually stereotyped as a loud kind of music. The colour scheme is followed through in both the text and images, with red, brown black and white dominating. These colours are fairly gender-neutral, and fit in with the rock theme. The graphology is generally spiky, hard-edged text which suggests a tough male audience. The models are all male rock musicians except one unknown female model used in a valentine's day poster image, suggesting the male gaze of the male audience.
This magazine also reflects its 'rock fan' target audience: Males of a wide are range that think themselves a bit tough.
3) The Strad
The Strad is a classical music magazine.
The use of italics and thin, accentuated text suggests a more mature audience. It largely contains only three colours (red white and black), which is less than the other two magazines. This again suggests the maturity of the target audience as they do not need pretty colours to keep their attention. The cover also only uses one image, reinforcing the 'simple and clean' theme. The relative lack of text and images compared to the other two magazines gives the potential buyer less information about the magazine's content. Although this may not be very friendly and inviting for new potential buyers, it suggests exclusivity; buying it may make you feel like you are part of something not immediately accessible to the average person. this makes the buyer fee; like they are special and 'part of a group' which makes them more likely to buy the next issue.
once again, we see an image painted by the cover of the buyer: a more mature, patient person who enjoys being a part of something that feels exclusive.
Basically: a magazine's front cover is made exactly to appeal to fans of that specific genre. The person who would buy the magazine is like can be accurately guessed by simply looking at the front page.