Sure, there's nothing wrong with once a day. Or even once a month. But if you're a competitor playing catch-up -- which YPN is to Adsense -- then you'd want to have better even superior features to expect to win some market share. Timeliness of traffic reports may not be at the top of the list in the most important features folks running contextual advertising, but it sure is good to have :o)
Once a day, in the beginning of any trial, is too little too late. In order to make a adjustments you need to know NOW how things are working.
I run 4 adservers on my network, and if any one of them only reported my complete stats once a day, I would pull them. Time is money, and I need to know now if it is working, can be tweeked immediately to work, or if it is a wash. I'm not willing to sacrifice very much revenue for a beta test to begin with. So without 100% real time stats, and the fact that their FAQ on payments is contradictory, I am glad we were not one of the chosen few for beta. If it doesn't get better, we won't bother in the fall when they contact us post-beta.