https://steemit.com/tos.html
From the Terms of Service:
{ 17. User Conduct
17.1. When accessing or using the Services, you agree that you will not commit any unlawful act, and that you are solely responsible for your conduct while using our Services. Without limiting the generality of the foregoing, you agree that you will not:
..........
17.1.3. Use any robot, spider, crawler, scraper or other automated means or interface not provided by us to access our Services or to extract data; }
When you are buying the use of an upvoting service, you are [USING] a [ROBOT] to [ACCESS] the [SERVICES].
That is pretty clear that bots are forbidden and of course there IS a Terms of Service.
RE: Thinking about tomorrow, today. Reinvest and Power-Up!