The problem with this is that you need to be able to give your attention to more than one marketing push at a time. You have to already be planning the next push while you're working on the current one. Yes, you might have your attention taken up by the need to print brochures, but you have to also be considering how your next poster push is going to work out as well.
Why is this so important?
You can't have a break in your marketing. You have to be sure that you always have your next marketing project lined up as soon as possible. As I'm sure anyone who has worked on a marketing project is aware of, you can't always time things out perfectly.
Let's say you just finished up a postcard marketing push and now it's time to move onto a brochure one. Now, you had things set up so that your postcards would last you through the development of your brochures, so that by the time you need to print brochures your postcards will finish their run.
But there are some delays you weren't expecting. An artist takes longer than you planned, or maybe some other big project pops up, forcing you to delay your brochures a little. What ends up happening is that your postcards finish up but you have no follow up marketing because your brochures are behind.
Had you been focusing on more than one project from the beginning, then when you first send out those postcards, your brochures should already be halfway finished. A delay in them won't be nearly as devastating because you were already ahead of things.
This is a safety net that all businesses need. Working on only one marketing push at a time puts yourself in a very tight situation where a single error might end up costing you quite a few sales because you didn't have a strong enough marketing presence. I've seen it happen before, and I know other companies have had to deal with it.
Keep on top of things and plan far in advance with your marketing. Be sure you always not only know what comes next, but you're already almost finished with it. The farther you are ahead, the more control you're going to have over the situation. Grab hold of your marketing and stay in complete control of it.