Though the overall users bases are substantially different, the rest of the numbers concerning the two services are strikingly similar. What is interesting to note is, as we wrote about a couple of weeks ago, many more people tend to log in to their Facebook account regularly.

A bit of a note to you who might be considering advertising via either of the services — Though fewer people follow brands on Twitter than on Facebook, those who follow on Twitter are nearly 18 percent more likely to purchase something from that brand than those who follow a brand on Facebook.

How does Twitter stack up against Facebook when it comes to demographics and online activity? Digital Surgeons, an online marketing agency, has put together an infographic comparing the Facebook population to the Twitter population, and it shows that while the two are similar in many respects in terms of age, income and so on, there are also some crucial differences of interest to marketers and others looking to mine the data and pick a favorite platform. Among the biggest differences are that Twitter users seem to be more active, but less interested in following brands.

Here are a few of the key findings represented in the infographic, which was based on data from a Barracuda Networks survey as well as an analysis from Razorfish and other demographic breakdowns from a number of sources (although the data on Twitter in particular is a little old — the service now has 190 million users).

• 88 percent of people are aware of Facebook, while 87 percent are aware of Twitter
• 12 percent of Facebook users update their status every day vs. 52 percent for Twitter
• males make up 46 percent of Facebook users, and 48 percent of Twitter
• 30 percent access Facebook via mobile vs. 37 percent for Twitter
• 40 percent follow a brand on Facebook vs. 25 percent on Twitter
• 70 percent of Facebook users are outside the U.S. vs. 60 percent for Twitter