Twitter spam is a message sent via tweet or direct message that includes a link in it to another web site. Here is a typical spam message:

There is a rumor/bad blog going around about you http://t.co/i0jd9 you might want to check it out

Here is another sample spam message sent from direct message:

Someone got really personal about you in their updates @ http://t.co/qtckd3

Some Twitter users use an autoresponder to reply to new followers. We don't necessarily consider that spam. These are real people with real accounts who actually use a paid, autoresponder service.

Other Twitter users use True Twit validation. True Twit validation was likely created because of Twitter spam. In order to become friends with a Twitter user who uses it, you must click on the link in their autoresponder. We don't consider that spam either because it seems reasonable at this time.