Activate uses numerous data points like Twitter followers-to-following ratio, engagement, and activity to calculate fee for Targeted Twitter campaigns. As you grow your influence on Twitter, you will see your fee going up accordingly.
We cannot tell you exactly why your twitter fee is different than your friends, because there are a number of variables; however, it could have to do with your follower-to-following ratio and the engagements you have on your tweets. The best thing you can do is to have find a balanced follower-to-following ratio and increase engagements on your tweets.
Our algorithm figures out the fee for every influencer; it is not done manually by us, nor do we have the ability to change any influencer's fee.
For more information, check out this great blog post.