Twitter Marketing is cool, it’s hot, but is it effective? For example, list building has been a primary activity for online marketers for years, but now newbies are getting confused. How does Twitter marketing help in list building? Can your followers be considered a list? If so, how effective is a Twitter list compared to an e-mail list?

Before web 2.0, there was only one kind of list. An e-mail list. Home marketers spent all their time trying to build their list, then market to that list with e-mail blasts and auto-responders. But now web 2.0 has changed the whole concept of list building. In addition to an e-mail list, we can reach out to friends on Facebook, Twitter, Youtube, Skype, Myspace, and a plethora of other social sites.

So, are your followers, friends, subscribers etc. all part of your list? Personally, I think so. But they all have different value, and should all be treated differently. For example, when a prospect receives an e-mail they have to act on it. They either read it, delete it, or mark it as spam. But a tweet doesn’t require any action at all. As a matter of fact, most tweets go completely unnoticed. So how do Tweets compare to e-mails?

Case Study.

Last week I did a simple test. I promoted a webinar with only two methods, Twitter and an e-mail blast. I sent the blast to 9,167 people. I advertised the same event to 21,745 Twitter followers in 4 different accounts. Here are the results:

E-mail blast: Sent to 9,167 recipients, out of which 467 bounced, leaving a total of 8,700. It’s impossible to say how many of those actually got into peoples inboxes, as e-mail is such an imperfect science, but I do know that 155 people clicked on the link, a conversion of 1.8%, or 18 respondents out of a thousand.

Twitter marketing: 21,745 followers received the Tweet. There are no bounces in Twitter, the delivery is 100%. And I had the added benefit of my post being re-tweeted by five other people, giving my promotion a boost. I don’t know how many followers they had, or how many clicks they got, because they used the same link. 151 people clicked on the link delivered through Twitter. So if we ignore the re-tweets, that’s a conversion of .7 percent. or 7 respondents per thousand.

So… if this one, non-scientific, test turns out to be accurate moving forward, it appears that an e-mail list is about 2.5 times as powerful as a Twitter list. Or, viewed another way, you have to have 2.5 times as many Twitter followers to get the same results as an e-mail blast.

So here’s the kicker: which is easier to get, 1,000 e-mail opt-ins or 2,500 Twitter followers? I think the answer is obvious. Twitter followers are a lot easier to get. So am I going to throw out my e-mail list? Of course not. And I still make offers to all my Twitter followers that invite them to opt-in to my e-mail list. But if they never opt in, the list is valuable by itself.

The bottom line is simple: responsible marketers should use all possible means of spreading their message, and take advantage of free services, like Twitter, that allow us instant access to people all around the world.