I've had some really bad experiences with bannings...I've had many tens of thousands of accounts suspended over time...actually hundreds of thousands in total over the last year if you include the accounts that I kamikazed. Also, many accounts that aren't suspended are "Ghosted" meaning when you follow someone, they don't get a notification about it (which is a primary way of getting followers back and traffic to your profile/affiliate offers) and tweets not being included in search results. It used to be that if I simply followed 1 million people across 10,000 accounts per day, I could make $5K+/day. Not so much anymore.
Here are a couple of things I know for a fact that they look at in terms of banning/ghosting (besides the usual stuff like excessive following):
1) Profile images. They do the same thing MySpace used to, which is that if you use the exact same image (with the same size) from a banned account, the new account gets banned/ghosted. I had to write a program that would take a single image and make into thousands of "different" images by changing things like compression ratio - same image just different settings. If the things you're doing on Twitter don't relate to your profile image, then you can always just use a scraper and collect images from MySpace or Facebook.
2) API. If you exclusively use the API to tweet, your accounts are automatically ghosted until you post some tweets "manually" from the web. That obviously is impossible if you are creating thousands of accounts per day. That's why I added the "post from web" feature on Super Duper Auto Tweeter - I wrote that program basically to solve my own problems.
3) Tweet content. If you retweet tweets that have been posted on banned accounts and those make up a significant majority of your total tweets on each account, or you just post the same thing across a bunch of different accounts, those accounts are headed for suspension very quickly. Even if the tweets are slightly different, but you use a common phrase or include the same URLs you could be in trouble (especially the same URL - you're dead to rights). This is why I added auto-url shortening and variable support to Super Duper Auto Tweeter.
4) IPs. They do look at IPs that you access the accounts with, but that by itself will not get all of your accounts banned.
5) Getting reported for spam. That's the single biggest problem - if you do manage to get your accounts situated so that new follower notifications are generated, people might actually visit your profile. Neither it, nor your tweet stream in general, can look spammy or you'll get enough spam reports and your account will be automatically suspended.
Bottom Line: There are two ways to approach Twitter marketing. One is to tread lightly, making sure you have different images, tweets, etc. You can get some traction out of this method if you're careful. The other is to go balls-to-the-walls and spam the crap out of everyone, knowing the account will die. I refer to these as kamikaze accounts. Even on a brand-new, ghosted account, if you post an @ reply, it shows up for the user when they do a search for @theirname, and those tweets often remain for some time even after an account is suspended. So in that strategy you instantly create an account and send out up to 300 @ replies (any more and the account will be automatically banned by Twitter, and all the tweets will disappear instantly) with links in them.
The basic premise of Twitter account suspension/ghosting is that it isn't any one thing. They look at a variety of factors (including those above), give them a score, and if you're over a certain thresh hold, you're toast.
You can still market on Twitter. It just takes an intelligent approach. The best thing to do is try many different strategies and see what has been working over the previous few days, since their anti-spam methods are constantly evolving.
Yes, me too. Im only using 1 IP.
I dont think they are checking the IP alone. There are lot of local networks in the world who are using routers that only have 1 public IP. Many wifi enabled areas are only using 1 public IP. So they cannot just suspend all those users.
