As seen on BHW...........
I don't know if this has been posted already or not so I will keep it short.
Go to each of these sites, and click start free. then click start getting followers and each site is supposed to send you 100 incoming followers...but it is more like 70-100... There is a pay option but if you use all 4 sites and click the free section then there is no need to pay... I usually change my password before and after each time as well just in case!
This method has worked for me for quite sometime and I get a thousand new followers every few days per twitter account!
The process only takes about 3-5 minutes per day! Hope this helps!