Here is how to create an auto DM (automated direct message) from your Twitter account to a new follower. For those who don't know, an Auto DM (or Automated Direct Message) is an instant message you get, that usually arrives in your email inbox, from the person who you just clicked to follow you in Twitter. You can access DMs in your side column of Twitter, or through a helpful application like TweetDeck. See below for the link of where you can access your personal DMs in Twitter. In theory, no one else can see them but you.
Once you have set this up, please share with us what you have chosen for your DM. What creative message did you think of? Auto DMs have been debated lately as a bad strategy, as they suggest laziness an wreek of infomertial-type people. So just be careful when you are creating them.
Go to TweetLater.com and register for an account.
Once you submit your registration, you may be taken to their newsletter page. Sign up or ignore this.
You'll need to log in again. Find the login button (as of this post, it's in the top right corner), and log on (even tho it seems like you would now be logged in, since you just created an account).
Now you must tell TweetLater about your Twitter account.
Click the blue +Twitter button in the top navigation.
Enter your Twitter username and password. I can't vouch for the level of security involved here. Making this decision is up to you.
Scroll down a bit and click the "Auto Welcome" button.
Also on this page, you can select if you'd like to auto follow those who follow you, or auto unfollow those who unfollow you. However, Twitter just decided to do away with the auto-follow feature because it seems disingenuous (which is my philosophy as well...and thanks @pegsamuel of @socialdiva for this Twitter Tip-off). TweetLater can provide this because they have worked with Twitter's API, which just means that Twitter allows them to use some of their technology to make fancy tools like this one.
The next question they ask you before you click "Save" is whether or not you want your @replies sent to you via email. @replies are the times that someone in Twitter is either talking to you or about you. This could be handy if you can't check your replies as often as you'd like. You can always see your replies in TweetDeck (for your computer), on Twitter itself (online), in Tweetie or Twitterific (on your phone) or other ways. You can also do a Twitter search for your name at search.twitter.com, or now from the new search box on the right side of your home page at Twitter.
NOTE: When I tested this, by way of following myself from another Twitter account, the DM did not come right away, or even for a few days. The Support people at TweetLater, who were very nice, told me that there was a delay/problem with the Twitter API that day, so things were a bit out of whack. It did send a day or two later.
If you've had success with the auto DM, do let us know in the Comments below. If you've noticed that you've actually lost followers (people who unfollow you in protest of your robotic DM), also let us know.
PS: You can also use TweetLater.com to auto opt out of DMs that are sent to you (um...would that be bad karma if you have created one and set up your account to send them...? Think about it.).