Changing the % is mainly to reserve your Voting Power.

For now, you'll need to give full votes to gain rewards, but in future, you can change the % say for comments - it's nice to upvote the best comments on your blog I think.

The bots will boost your rewards a little at times, but mostly they are not profitable and the money you pay is for 'advertising'.

Followers who are upvoting with commenting should comment so you can vote them :)