I think you mean that colleges ARE doing these things. Some of them... the ones I think they are not doing:

What would happen if the statistics of incoming freshman and graduates were used to solicit new customers?

Good luck trying to get a clear picture of outcomes from any college other than anecdotal stories about a few specific grads. They trumpet the stats of the incoming fresman class, but it is very, very difficult to get clear, consistent information on outcomes.

Or had the idea that giving someone money now signficantly increases the chance that person will give considerably more money later on?

Possibly merit money is granted with this as at least a portion of their thinking (if I thought they were looking at the long term, but that is actually also somewhat questionable). I don't see it for need based aid -- it isn't like those students come from big money families, and who knows if they will be financially successful enough to give money back to the college later if that is not the case? Now I think colleges do grant ADMISSION to students from families with a lot of money if the family has made significant contributions in the past to the school.