I run payroll, and everytime I do it's a potential mistake waiting to be made. We use Gusto, which is about as good as it gets for online / easy payroll, and there are still occasional issues. Payroll doesn't just pay an employee, it also handles proper withholding for each employee with an ever changing system that is tied to a huge swath of federal/state/city tax rules, which includes how often you have to pay the locality, usually based on how big payroll was in that locality. Basically, doing this everyday, having it trickle in, seems like a nightmare. I think for it to work properly the end to end system needs to be reworked, and I don't think the potential benefits outweigh the risk and work required.