This is the last installment of our “Introduction to Social Media” series. Please reference previous articles to get a better understanding of how to start utilizing Social Media for your company.

Last article, the “big three” social media sites were introduced (Facebook, Twitter and LinkedIn). While three cuts down the field into a manageable number, it’s not always practical to immediately start pages on all of the big social media sites right away. Managing social media sites can take a lot of time, so unless you’re working with experts it’s better to ease yourself in. So which site should you start with?

LinkedIn can immediately be taken out of the race. As a specialized site that focuses on networking and job postings, it’s neither a “normal” social media site nor a place where you can reach customers. LinkedIn is still a useful site, but it does not make up a core part of a company’s social media presence. This leaves two options: Facebook and Twitter.

Facebook is an outstanding platform for businesses. Fan pages allow for high degrees of customization and enable many different avenues of customer interaction. Facebook also boasts the most developed advertising system in social media, allowing you to post ads that display only to your chosen target demographics. There are many ways to tweak your advertising plan, and Facebook provides you with analytics in a way similar to Google AdWords that allows you to study the effectiveness of different advertising approaches so that you can get the most out of your marketing dollar.

Twitter is a minimalist social media site by nature. Twitter is also a site that runs in “real time:” messages are sent out, favorited, retweeted and replied to instantly, coming closer to emulating text messages than the forums and message boards that other social media sites like Facebook echo. Word spreads quickly on Twitter. You might not be able to interact with customers in the same involved way as Facebook, but you have a wider, public set of postings to pull from and can easily reply to anyone who is talking about your company.

Unfortunately, Twitter has some large negatives in its advertising platform. First, advertising is limited, without the micromanaging, demographic-targeting abilities of Facebook. Twitter only allows you to created promoted trends and tweets. Unless you focus on promoted tweets that appear in response to searches that Twitter users make, Twitter’s advertising methods are probably not very useful for smaller businesses – you see companies like Samsung promote trends for new phones, not smaller businesses advertising a service.

Twitter’s advertising success is also not proven: no one is entirely sure how effective Twitter advertising is. Facebook provides easy advertising analysis and generally predictable ad prices that are a foil to Twitter’s newer system. While Twitter can certainly provide marketing success, it just doesn’t seem to measure up to Facebook’s more structured approach.

If you have to choose just one social media site to put time and money into, make it Facebook. Facebook has incredible advertising options that enable you to create a comprehensive social media marketing plan. It’s never a bad idea to pick up a Twitter account. In fact, having a presence of any level on both Facebook and Twitter is highly recommended. But if you have to carefully allocate your time and money, put it towards Facebook.