Activist investor Icahn uses Twitter to announce new letter to Dell shareholders

Activist investor Carl Icahn still hasn't got bored of Twitter. After adding $14bn to Apple's value with a single Tweet he's back on old ground, talking Dell.

That's Icahn's 17th Tweet, and follows multiple takeover rejections by Dell's bid committee.

Regardless, it will be interesting to see market reaction when Dell shares begin trading at 2.30pm. Maybe more than the letter itself.

The more that Icahn uses Twitter to make announcements, the smaller his impact on the platform is likely to be.