This is a guest post written by Tal Raviv, Chief Bug Creator at Ecquire At Ecquire we believe the most important measure of a product is its referability. We don’t use words like “finished” or “minimum viable product” or “good enough” It’s either referable or it’s not. A user either feels confident enough to put their reputation on the line for your product – or your marketing is going to be very expensive. How do you measure referability? Aside from metrics like retention and observing growth and sources of growth – there’s an extremely direct way to do this… let your customers refer their friends right inside your app! How do we do this? Ecquire is a browser extension that allows you to send data from where you’re working (places like your email client or Linkedin, etc), to the places where it needs to be stored (like a customer database or email marketing solution – or even a Google spreadsheet). It’s free forever for under 15 contacts a month, and beyond that you can either pay a few bucks or you can refer a friend through our app to get more free transfers. So we thought up a small incentive to refer someone through our app – now, um crap, how are we going to send emails? We don’t have the developer resources to build that from scratch. More importantly, we need to know if our little experiment is working. We’ve got to be tracking if people really are referring their friends, and track whether their friends are opening and clicking on those referrals. Enter: SendGrid, to the rescue! With a simple call to their web services API – literally one line of code – we accomplished ALL of this in minutes. Beyond just sending the emails perfectly, SendGrid has an entire UI to easily visualize the success of this campaign and help us to decide if we want to invest more tech time developing out our referral program. If this looks promising, we can then build more features like rewarding for referrals that actually sign up (like DropBox) etc. But the beautiful thing is, we could run a full-fledged experiment on the effectiveness of referrals, without investing any time at all. This allows us to focus on our core product while leaving sending emails to the pros. Check out the quick video below to learn more about Ecquire: Pour me an Ecquire on the rocks from Ecquire on Vimeo.