I have no clue what this service does. None!
Are these invoices that the user's business _sends_ ? ( hence this is some form of AR management application) or are these invoices received by the user's business ? (hence an AP management application)
In either case, surely the business is already using some sort of accounting software and therefore what does this service do that regular Quickbooks doesn't do?
And finally: who sends or receives thousands of invoices per month and doesn't already have some decent management and reporting systems in place?
fwiw I worked on a startup that (I think, because we were solving the problem alluded to on the site of making sense of arbitrarily formatted business transaction documents) was trying to do the same thing about 15 years ago. We were targeting big corporations dealing with high-value invoices with a broken AR/AP process. It didn't end well, I think in part because there isn't a good value proposition here. It has to be "you'll get paid much sooner" or "fewer invoices will end up unpaid". Just being "nicer" or "easier" doesn't cut it.