There are innumerable small-scale programs that show limited positive results, but almost none of them scale up (see http://www.theatlantic.com/business/archive/2007/11/scale-ma... for more on that general problem; her book The Upside of Down is also good on this subject). Lots of small-scale Head Start programs show promise too, but the program's effects on the whole fade out after a couple years, and on a large scale it hasn't done anything except provide daycare and jobs.

Programs like "Nurse-Family Partnership – Top Tier" already operate. I know because I've written numerous Health Resources and Services Administration (HRSA) Healthy Start Initiative (HSI) proposals (see more about the program here: http://blog.seliger.com/2013/12/15/hrsas-healthy-start-initi...) that attempt to do just this. I do grant writing for nonprofit and public agencies, so I see citations like yours all the time. Next time I write an HSI or similar program, I'll cite "Nurse-Family Partnership – Top Tier." Doing so isn't going to make the program any better, because HSI has been operating for a couple decades, under different names, and hasn't accomplished much on a large scale, in part because of the scale-up problems described in the first paragraph.

Ideas like "Nurse-Family Partnership – Top Tier" sound good, but the gap between the real world and the proposal world is quite wide (http://blog.seliger.com/2010/04/11/the-real-world-and-the-pr...). Zuckerberg has evidently learned this.

Apologies for the length of this post, but the issue is a complex one that is hard to explain and harder to understand—hence all the links!