Hi @foody, see the instructions in part 1:
https://steemit.com/steemit/@trending/4-steps-to-boost-a-post-for-profit-with-minnowbooster
Bids are done in time-based rounds based on how the bot is setup, usually. Bots try to remain at 100% voting power (the voting power required to replenish a single 100% upvote is recharged after 2.4 hours), so they only offer a limited number of upvotes and divide their voting power based on how much is bid. If 100% voting power is offered once every 2.4 hours, and sandy bids 1 SBD and jerry bids 2 SBD during that 2.4 hour round, sandy gets a 33.33% upvote and jerry gets a 66% upvote. They don't all work like this, but that's how the bidding bots works.
It's pretty simple to use once you get the hang of it, just make sure you use it on good, unique posts or you'll be blacklisted and downvoted quickly.
This comment has received a 3.13 % upvote from @drotto thanks to: @trending.