Improvements on my first draft

After making adjustments

Before making adjustments

I've moved the masthead further to the left to make it look more like a magazine front cover and less like a poster.
To make the main sell line stand out more, I've added the purple box behind it.
I've moved the teasing contents panel to the bottom as I thought it might just look a bit better there instead of further up.  It also helps to bring more attention to the main sell line, along with the purple box.
I was also informed that the masthead didn't seem to match the style of the rest of the front cover.  To overcome this, I changed the bars behind the text from grey to purple to bring it into the colour scheme. The same thing would be done with each issue, depending on each individual colour scheme.