These bot promotions really need to stop with the 100% ROI quotation.
Bid Bots pay anywhere from 80 to 100% of SBD received from upvote purchases. Additional some bots have started sharing curation rewards (in this case 50% of curation rewards are shared with delegators).
An investors actual ROI (Return on Investment) is ~20 to 40% APR depending on many factors. This is still a fantastic return on your Steem investment (just compare it to stock market returns, bonds or CDs). This does not include the potential for Steem Price to increase over time.
The more clear BidBot owners are upfront the less complaints that will be received later on.