Yes. In my case I have realized that I am just simply too busy writing my own rather long posts, and marketing them, and doing all of my other freelance work that I simply don't the have the time/energy to manually vote as much as I should, so I will be using Steemvoter to pick up the slack so that the posters I most like can be sure to get my upvotes and I can also maximize my Steemit income, and have the ability to go back and read the posts if/when I have the time. I don't see any ethical issues if you use the tool in this way.