If you check this post, then you can see that I received an upvote from steembasicincome that is the SBI account. I had 50HP delegated to them till now. The reward did accumulate quite a lot, as I was not posting for over a month I think.

They have also another feature, where you send them a HIVE (corrected from HBD according to the below response), and then they will upvote your posts forever. The upvote depends on the amount of HIVE (corrected from HBD according to the below response) you sent to them.