What we've found is:
1. Managers like the transparency of knowing how their employees are spending money. Many managers today actually have to nag their team to get their expenses in before they close the books. This more up-to-date information about how money is getting spent can often be helpful to the manager.
2. Approving expenses in Abacus is stupidly easy, and it shows that you love your employees. Companies (especially in tech) compete so hard to make employees happy (snacks, benefits, etc.) and Abacus is one of the easiest ways to make your employees happier. Rather than treating employees 'guilty until proven innocent' and making them wait months to get paid back for their legitimate business expenses, Abacus lets you easily reimburse your employees, which you're going to do anyway. Win win
3. It's actually a time saver. Abacus syncs directly with your bookkeeping software (time-saver) and we automatically categorize expenses, based on the vendor info we pull from foursquare (time-saver). We've also built the conversation directly into Abacus, so you can comment on any expense that needs further clarification, rather then trying to hunt someone down over email about some confusing expense from 2 months ago (time-saver). The net effect is a much tighter, faster feedback loop.