I just read a post on here about twitter marketing. It was a very insightful post about marketing yourself on twitter and being more social.
But like anything that is social online it takes time to see GREAT results. Even though the subject was "twitter marketing" which talked about getting more retweets and asking followers questions about related things not pertaining to their music business I looked at it as way to social proof your online presence rather than marketing.
The thing with twitter is you have can't be aggressive in your promotional efforts because people will start to ignore you on there. You have to blend in and do your money shot promotions every now and then. And even when you do that you still have to be cool at the same time.
Though the advice about social proofing is good it is almost useless if you are trying to see any revenue from artists on there who interact with you that want beats. But this not only applies to producers but anyone who wants to marketing on twitter for that matter...
The most efficient way to market on twitter is to get followers and than tell them about what you do and take them off twitter onto your website.
There are many tools that you can use to get targeted followers. Just know that when go that route consider the 80/20 rule (Google: Pareto principle). If you follow 1000 people expect to get about 100 followers out of that in the same day.
Anywhere from 10% to 20% follow back ratio is normal and everyone that follows you back send them a mention thanking them for following you and send them your link back to your site.
That way you won't have to deal with trying to get your message through to them with all of noise that social media brings on the daily.
And to make sure you don't waste your efforts have them opt in to your mailing list so that you can message them new material in the future without having to deal with twitter all the time.
Take advantage of twitter as much as possible if you value it in that manner because at the end of the day you don't own that account.....twitter does.
This is great to do if you are on a very limited budget and can't pay for faster traffic (quality traffic in large amounts)...