That rule was probably put in place to avoid possible abuse in the reward pool. Some people immediately send in the bots minutes after the post is created.
This is not seen as a problem when the bids are below $20, but is another story when people send in over $100. It might also seen as rude as people who upvote the post after 30minutes will get less or no curation rewards at all.
I see many people have the idea about buying bot upvote at a later time for the benefits of early minnow upvoters. But if we dived into the figures, I don't think those early minnows could get any meaningful curation reward at all. On the contrary, a large part of the vote value (25% at most) will be shared back to the bot. Late bot upvote is therefore benefit to the bot rather than to the early minnows.
To reward minnow upvoters, the best way I think is to directly upvote their post or comment.
Just my two cents :)
Agree! I always try to upvote any replies to my post as well :)
As to the issue of minnows not getting 'meaningful' curation rewards, hard to admit but I agree with this as well lol.
Their however is a significant increase on the curation reward if the bots vote after the minnows, a minnow will most likely get around $0.10-$0.15 instead of the usual $0.001 SP. A definite increase but kind of useless one :)
I enjoy this nice and fruitful discussion with you :)
In my previous experiment, I was a relative early upvoter on a post. At the time I upvoted, it was at $1.87. Later on all the bots came in. That post ended up over $400. My curation reward was only 0.012 SP.
May be it was because my STEEM POWER was too low.
Sounds about right. I had the same experience. Upvoted at exactly 30minutes at 100% with payout less than $5, and got around $0.011 SP in reward. My SP at that time was at 60.
Moral of the story, if your SP is less than 1k or 500, don't depend on curation rewards. :)