Since Twitter becomes a new way to communicate on cyber world, it does not mean that you are free to do anything that can annoy other people. Just like the real world, you need to have etiquette while on Twitter. Learn not to hurt other people with something you wrote. Try to avoid spamming, as it can be disturbance for many people.
Twitter can be a good way to promote such products or services. And Twitters allows you to send your promotional tweet to many with just one single click. It is okay to send such like that, but make sure that it is informative because there are many who just send blank links that will waste time clicking on it. No one likes sarcastic or hating tweets, so make sure you do the same. Be nice and avoid mocking or cursing someone even he or she does not have Twitter account.
Don’t be “antisocial” meaning that someone reply your tweets, spend some time to reply them, do not have to be long, but “thanks” or just say hi is better rather than ignore them. In this case, silent is no longer golden. There are many Twitter etiquettes, but you can learn this by experience, the more you use Twitter, the more you will understand every bit about it.