I use Tweetlater to automate tweets every 35 minutes, over 10 accounts. Don't feel like adding up all the followers but it's somewhere in the 4-5k range. You can avoid getting reported for spamming on there simply by using RT @randomnamehere yourmessagehere yoururlhere, most people think you're just replying to someone elses question and won't report. 0 bans after 1,820 tweets total now.
If something doesn't work for you, don't consider it "broken", figure out what you need to change to optimize it. For example find a way to get people to follow you. :banana: