Variety is Key

A fellow artist friend recently asked how to land advertising jobs with agencies~ the big projects?! Honestly, the more I think about it the more I realize that it has a lot to do with the amount of work in your portfolio. 8-12 pieces is not enough to have in your portfolio anymore. Not if you want to be a commercial artist. You need to show a vast variety of subject matter. You need to view your portfolio as a 'history' in a way. I'm not saying put low quality pieces in your portfolio, but show the client all of your skills, your experience. 
When I was in school, I was always told I had too much work in my portfolio and that it was stylistically too 'all over the place.' Ironically, that's the same reason why I was able to develop a career in this field. Stylistically, I work differently from project to project and it never gets old. Most of my idols from my childhood always complain about being tired of drawing the same style over and over. I don't have that problem. So! Don't be afraid if you like to work in different styles and on a variety of subject matters. Variety is key, BUT you need to stay organized. Your website is your everything. It represents you and your work. It represents your past, it represents your present and it shows off your future potential. :)