Being on Twitter and using Twitter are two very different things. In august this year Mashable reported that large number of Fortune 100 companies have taken to Twitter. But are they really using it? A study released today (PDF) by Weber Shandwick says the answer is not positive, and that the majority of Fortune 100 companies don’t really get Twitter. Though 73 of 100 companies had at least one registered Twitter account (up from 54 reported in an unrelated study released in August), the majority of them are not using Twitter effectively to engage their followers, weren’t tweeting often, and didn’t display any personality in their tweets, according to the study.

Low engagement of followers seems to be a reason for the ineffectiveness of Fortune 100. Out of the 540 total Twitter accounts registered by Fortune 100 companies, 50 percent of the accounts had fewer than 500 followers and another 15 percent weren’t being used at all. Twitter is more about the personality of the brand the user; not the brand/product alone! Out of the 540 accounts, 53 percent “did not display personality, tone or voice on their account pages,” according to the report, which judged personality based on whether an account was identified with a personality who posted on behalf of the company or if it was a “faceless” brand account. A real name to an account adds much higher credibility and a human face.

However, 32 percent did have personalities that were associated with their accounts, which might be a better approach to creating an account that is engaging and personable for consumers. Personality can also be demonstrated on Twitter via the writing of the actual tweets. Though tweeting sparingly can be a good thing, 76 percent of the accounts had fewer than 500 tweets posted.

The most popular use of Twitter from companies using it, is as a newsfeed or for developing brand awareness. But companies seem not to understand how to use the service to increase sales or they don’t believe that it’s possible. Though Dell (33 on Fortune 100 list) has used Twitter to sell millions of dollars worth of products, only 16 percent of Fortune 100 accounts used Twitter for sales, special Twitter offers, coupons or other special offers.

Another effective use for businesses has been using Twitter for customer service. For It very well may be that these companies are steering away from customer service because to do it effectively, they would need additional staff specifically to respond to complaints and questions from customers on Twitter.

When these companies do take a look at their strategy and use of social media, they need to realize that the key element missing is conversation. Twitter, and social media in general, is about two-way communication, which is something that all companies need to realize as they constantly evaluate and tweak their social media use. Companies should also reconsider whether to use a person that is identified with an account, which could improve their engagement and build a personable brand.