Aside from the standard media channels, where else do you market your startup?

Hiring fairs at university campuses is a sneaky place to market and data mine

physical events such conferences, seminars etc

The best advice I ever got for marketing was "right place, right time". For us, it was finding a news aggregator site in our niche. News aggregators, good ones, are a great find. Their model actively encourages community to submit articles since the aggregator needs a steady flow of fresh and relevant news for their community. This was a great match for us, a startup with a new product who needed to spread the word about our product. We struck up a relationship with the owner of the site and we have been posting regularly. We owe most of our organic growth to this one tactic, it helped us get started. Hope this helps!