From experience, go for 50, maybe 60 systems per day. More than that is wasted.
I did the 50-60 systems thing, with system data, not paying any attention to scans or anything, and didn't get anywhere close to worthwhile results.
Upon making the thread I was told also that system data worth 10 million should be the appropriate threshold for a 9.5mil pop system.
I'm aware of only doing data drops by system, never by page. It's still unclear how CR value weighs your contribution compared to transaction count, but I suppose I'll test and see...
I've been out in the black a while and had about 500+ systems casually scanned not knowing what I was doing, and have sinceforth as I approach 1k total systems developed a way to economize my time/money gain. I'm doing a classic trip to Colonia and then to Sag A.... on Economy.
I should be back to Sol with about 2k+ systems worth.
I certainly hope there's no soft cap for player contribution to the bucket.