In an earlier post I wrote about what makes a good Tweet. The best Tweets are those that make me laugh or provide me with an interesting insight or make me look at something differently I follow about 150 people on Twitter and I have a pretty high bar for what I keep in my timeline. If a Tweeter isn't adding some kind of consistent value in those 140 characters, I'll stop following them.
There are a lot of similarities between being a good Tweeter and a good marketer. If what you're saying to prospects/clients isn't highly valuable and said very efficiently, it's a matter of time before they tune you out.
I've begun pushing my team to have "Twitter-like" conversations with clients and prospects; I've also heard this referred to as "drip marketing". That is, provide the client with regular, short and highly interesting/engaging/insightful pieces of information (most often without an ask) that educate the recipient and -- just as importantly -- change their perception of what you do in a favorable way. I like to think of these as small, mutual gifts -- they provide both parties with some benefit.
Ideally, I've asked my team to try to keep their drip emails down to 140 characters, though depending on the message this can be quite challenging.
Regardless, the aspiration is simple: be really concise and be really interesting.