Twitter Tactics: When Do You Block?

To the folks out there twittering, do you block followers?  Which ones?  My rate of new followers is slow enough that I can and do hit each follower's profile to discern whether the person is real or not. 

• Bots get blocked.  Some are easier to figure out so I don't even need to look at their profile, but some do.  The latest trend seems to be bots with pics that are not as suggestive and with the short profiles that are no so suggestive, but doing to their longer profile reveals a weblink with a key word or two that gives it away. 
• I also block people who are real but whose profile is a sales pitch.  While one can argue that everyone on twitter is selling themselves, when the profile is an ad for stuff, I block them.

Does my blocking become less rigorous when I am about to reach a new threshold of followers?  Um, sure.  But now that I have reached a particular level, I am less concerned about the ego-gratification of having heaps of followers.  So, this was a morning of blocking and reporting of spam folks.


Do you bother?  Are there categories of folks you block that I have not included here?   And yes, blocking a follower is easier than de-friending in facebook or in person.  I have yet to block an overly enthusiastic retweeter/commenter, but the temptation does exist.