A band is a business. You're in the business of entertaining an audience, and you're in the business of building yourself up as a celebrity to sell physical products to your adoring fans (CD's, downloads, t-shirts, concert tickets....). Essentially a band is a retailer that sells a specialized product.
So if a band is a business, what role do its members play?
Having clearly defined roles within the band for each member and holding them accountable for not fulfilling those roles can help avoid certain troubles down the road. But before you can have defined roles, you should write down what your goals are and determine the best member of the band to handle certain tasks aimed at helping you reach those goals.
But then comes the part that a lot of bands overlook, and yes I'll admit that I'm guilty of this myself. That is a written band agreement. A business usually has a contract signed by all parties outlining what the goals are, and what the business aims to do. This way, there's a legal document allowing the business to hold itself, and others, accountable. But most bands operate on handshake deals and never write anything down. They fail to clearly define the terms of deals they make, and when the deal goes south they feel ripped off. This could happen if a band determines that it's in the band's best interest to replace a member, but the member has invested capital or property collateral into a business venture for the betterment of the band. If those terms were not done in writing so that all sides understand the terms of that members’ investment, then a situation like this could result in a lot of hurt feelings and possible legal action.
I've seen it happen multiple times. I myself was in a band 11 years ago, and a few years after the band broke up I was informed through hearsay that one of the former members was considering legal action for the cost of the CD's they paid to duplicate that they were now sitting on. Whether or not this is actually true, I do not know. It was hearsay, but if it were true, this would've been something we could've avoided if the terms of each members contributions and their role in the band were clearly defined in writing.
How you divide the positions in a band should play on the band members’ strengths. If a band member isn't very computer savvy, but they are good with face to face interactions, maybe they should be a public face of the band to represent them in the scene. This doesn't mean others can't do this role, but perhaps this should be that member's primary area of focus.
If a band member is good with administrative work, perhaps they should do the administrative work for the band. This could include keeping records, drawing up contracts, tracking sales data, acting as an accountant/treasurer for the band, etc.
If a band member is a social media whore, perhaps they should represent the bands online activities. This person, acting as the band, would engage the public on social media profiles to help build that online social connection of loyal fans.
Having clearly defined roles that play on the strengths of the individual band members can help the bands members keep focused on the areas that they are most productive, and allow the rest of the band to see easily when someone isn't pulling their weight.
But, and I can't stress this enough, this should all be defined in writing. This is a business venture, no matter how big or small your goals are. You need to have the terms of the agreement in writing so that when something happens (it always does) you know how you've all agreed to handle it.