It sounds like going the free route was a mistake. Bootstrapped startups have to charge something to somebody, and you-pay-me-for-my-product is a time tested way of doing it.
As for the rest, you need to tamp down your costs. $30/day is extremely high for a bootstrapped, no-revenue startup. Find a way to cut this down. Based on your comments about GAE and SQS, see about moving to a standalone VPS (Slicehost or whatever) and running your own ActiveMQ server, probably on the same machine. It's hard for me to imagine a web app w/ less than 10k users needing more than a single big VPS.