It is a way of promoting one's photography with the free-market system. Having a free-market that allows one to promote their work also increases the value of STEEM/SBD by adding to the STEEM-based economy.
There are now many apps based on the STEEM blockchain that are adding value (a use) for STEEM, rather than selling STEEM/SBD into an exchange for fiat which drives down the value of STEEM. Bidbots are just one of many parts of the STEEM-based economy.
The better I think the my photograph's are, the more I promote them. Based on the comments I get, the promotion is serving its purpose of exposing my photography to more people on SteemIt.
To give back to the SteemIt community I upvote every unique comment I get on my blog posts not generated by a bot.
Have a great week!
Steem on,
Mike
Having free-market mentioned as a justification usually is a dead end. It doesn't work unchecked. On a 'decentralized' platform that would be your responsibilty.
Enjoy the steem, but you are not earning your rep.