Just this week I finished a project that involved creating a Twitter strategy for a group of Cleantech companies. Looking at the growing relevance of Twitter on the internet (see Sysomos or Comscore), I must say it would be a grave mistake for these companies to ignore Twitter. As a Twitter user, I must also say, please don't see Twitter as just another marketing channel.
Twitter did not occupy much of my time after I first registered as @this_moment but has become a fixed part of my daily routines ever since I discovered hootsuite.com (and opened up @ines_doodles as second account). So my personal behavior in a way humbly reflects the tremendous growth that Twitter has seen in the last months
What I have also seen growing is the number of accounts by small and medium size companies. Unfortunately, many of their tweets I can only regard as spam: Mentioning brand names over and over again quickly bores followers and does nothing to improve the image of the company. In fact, the more companies come to Twitter, the more impatient Twitteristi become with one-way-messages. It even seems that a growing share of the conversation on Twitter is about blocking spam - but that may just be my personal impression. 