Don't spam
Several brands have failed with Twitter because they don’t really understand how people use it. The platform is social. If you are intrusive, you will alienate the people you want to win over.
Tweet links to blog posts, comments, thoughts, questions, and even special offers now and again. But don’t simply pour out sales pitches. People won’t follow you, and anyone encountering your tweets will soon get irritated with you and your brand.
Following thousands of people to try and build your own follower numbers is also a questionable tactic, even if you aren’t sending them sales pitches. Avoid, in favour of forming fewer, more authentic connections with key individuals.