I remember working at a few places and the hardest thing to deal with had nothing to do with the business itself, but all to do with communication. If you start or are a part of anything that deals with the population around you than at some point you will realize that it doesn't matter how great your services are if you can't talk to your clients about it. If you want to grow your company this issue is even greater. Now imagine being a client or customer on the other side of this communication issue. No matter how you look at it, the problem is prohibiting.
So, when you are facing communication issues on a basic level you need to correct the problem. You can hire people who are polyglots, but it may not be possible to have them on hand all the time for every language and situation. That's when you have to find someone who offers translations services. Their are some things to consider when making your choice in whom to use for your services.
First, what are the primary language needs that your clients have? Chances are their is more than one language a client has a need in so narrowing it down to the most needed and noting the others is important. Now that you have your list evaluate the cost in hiring someone for each of those needs, frequency of use, and the cost of a translation company. You may find that hiring someone for the #1 language on your list makes the most sense for your company. I would bet that past maybe your top #3 it wouldn't make sense to have a full time staffer for each language. You may not even find it to be beneficial to have anything past the #1 language in your needs list.
Next, look for a company based on the services you need and what they offer. Do they offer translation in just one communication method or a variety of methods. Some companies only offer group translation while others offer one on one only. I personally think finding a company that offers both is the best way to cover all potential issues. You also need to consider the area of specialty in which your translator best operates. You don't want a legal translator trying to make sense out of medical translations. Making sure you have the right company to meet your needs is important.
Lastly, look at cost. Decide in your business plan how much you can through at this problem to resolve it. Setting aside a specific amount of money based on need, frequency, and available funds will narrow down your choices as you seek a professional. Remember that often you get what you pay for, but never want to over pay so middle to high middle of the cost spectrum is probably the best bet for your dollar.
If your looking for a way to help move the company you work for forward to expand your clientele than I would start by looking at communication and then go from their. You can't have a client if you can't somehow speak their language.