140-character limits are gone on Twitter — at least in their direct messages.

On Aug. 12, Twitter expanded their 140-character limit to 10,000 within direct messages. Yes, that's over a 7,000 percent space increase. Also, you can now direct message anyone not just those with whom you have a connection already.

How should your brand take advantage of this Twitter expansion? Discover the do's and don'ts of sending brand messages through Twitter's direct messages below.

Do: Use direct messages for customer service.

In February 2015 alone, customers sent an incredible 5.5 million tweets directed at brands. Twitter and social media at large has become the 24/7 customer hotline. As soon as shoppers become unhappy, they'll send a tweet your way.

Now, you no longer have to solve their problem in 140 characters. For brands, this is one of the best benefits of Twitter's new updates.

When responding to unhappy customer tweets, send a tweet first before resolving it privately. You want their followers to see that you hear them and want to remedy the problem through a direct message.

From here, respond through a direct message in the same fashion you would through email. Of course, keep it as concise as you can since attention spans are short especially on social media.

Don't: Send an automatic direct message to new followers.

Direct messages thanking new followers for following you paint you as an inauthentic brand. A canned direct message blasted out to all new followers sends the wrong message to new, impressionable followers. In fact, more often than not, you'll lose the new follow instantly because of this.

Instead, skip the direct message and send a tweet mentioning them. Here, you can keep it genuine and personal. Call out something you like about their feed, profile or bio. Now that will get their attention in a good way.

Do: Connect with media and all-star customers through direct messages.

Instead, use your direct messages to personally connect with individuals. If you can't find the email address of a media contact, send him/her a direct message on Twitter. Or if you sent a couple emails without a response, send a brief direct message to get attention.

Media contacts get thousands of emails a day, so messages easily slip through the cracks. Sending a direct message on Twitter lets you stand out, be memorable and secure a response.

Likewise, send direct, personal messages to customers who consistently write positive tweets about your business. Or connect with your all-star shoppers, those who come back to you time and time again. A personal thank-you note even if it's digital shows how much you care and value them.

Don't: Send spam-like, marketing "emails" in direct messages.

The ability to send long, direct messages to anyone does not mean you should blast them out in lieu of email. People classify them as spam, dislike receiving them and often dislike your brand by association.

When people sign up, they can then opt-out of your brand emails. The same isn't true for Twitter direct messages. Don't mass-send canned messages to anyone who didn't ask for them.

You could, however, start a Twitter newsletter. Ask people to sign up, then send marketing messages through direct messages.