"Spam" as a verb can connote unsolicited commercial messages, especially email, but in a broader sense is often used to mean aggressive, repeated broadcasting o

"Spam" as a verb can connote unsolicited commercial messages, especially email, but in a broader sense is often used to mean aggressive, repeated broadcasting or emission of some kind, generally less malicious than actual traditional email spam. E.g., "I was spamming grenades in Quake like nobody's business." to mean that you were rapidly, indiscriminately shooting grenades in the hope of blanketing an area with grenade explosions in order to score an easy kill. In that sense, sending the same Twitter message over and over seems like typical spammy behavior. The marketing/commercial focus of it is also somewhat similar to a spammer, since spam is done for profit. Finally, technically when a spammer makes fake accounts full of affiliate marketing links and the like and then follows everyone he can find, that's him doing what he wants (spamming) with his Twitter feed as well. Many of them still don't @message people yet.