First stop looking for "online marketing"
That's a old fashioned term from when the internet was fresh and the new breed of marketers needed to distinguish themselves from
traditional marketers. That distinction continues to evolve with digital marketer, internet marketer, and more recently "Growth Hacker" or Mar/Tech being the nom de jour.
Fact is this. The internet's technology has enabled marketing (marketers) to be analytical, real-time, search based, optimization oriented like never before. Anyone who isn't capable of "online" is being retired as quickly as we can pass a National pension and retirement program ;)
What you're going to get when you look for an "online marketing" candidate is a more often than not, a Jr. professional or one who claims to be online so as to broaden the scope of their resume.
Search out a Marketing Director or higher to get the experience you need and look to the skills you're seeking for this particular job.
Based on your tags it looks like you want Product Marketing. What else? Content marketing? Social marketing?
- Search Marketing and SEO
- Analytics & statistics
- Web development (yes, Good marketers can do this)
- Marketing automation
- CRM
- A/B testing or multivariate testing
- Content marketing
- Social marketing
- Product marketing
- Design