Many applications have come and gone that allowed you to send a direct message to all your twitter followers. Twitter recently reduced the number of Direct Messages you can send in one day to 250. That leaves the market for automated direct message sending with less competition.
You can manually send a direct message to other Twitter users, but it's to laborious to use that method if you have thousands of followers. To send a direct message to all your followers you need to use Tweetadder. You can download Tweetadder from the resource link section below. Tweetadder automates the direct message process so you set it up once and forget about it.
Download and Install Tweetadder (link in resource section below)
Open Tweetadder and add your Twitter account.
Double click on your Twitter account to open the management window.
Click on the messages tab.
In the messages to send text box enter the message you want to send in less than 140 characters (including the link). Click Add.
Under Message Settings type in the number of direct messages you want to send per day (less than 250).
Next click on the automation tab.
Click the check box "do the following tasks each day at" and select at time
Select the check box - Automatically send messages
Sit back and relax, Tweetadder will send your Direct Message to all your followers at a rate of 250 (or less) per day until they have all received your message.