One way we (Zapier) got early users in the door was by trolling forums. We would manually search the internet for people complaining about integrations that did

One way we (Zapier) got early users in the door was by trolling forums. We would manually search the internet for people complaining about integrations that didn't exist (eg. http://webapps.stackexchange.com/questions/13007/how-can-i-auto-import-contacts-from-paypal-into-highrise http://webapps.stackexchange.com/questions/13007/how-can-i-a...). We would follow up directly, build the integration, and instantly have a new customer. Clearly this doesn't scale [or does it?] but it put us on the right track early when we weren't sure what people would respond to.