I feel the comments that you need to hire or partner make sense. If the latter you might feel you are giving a chunk of the business away but if you are walking away anyway you're already loosing 100%.
Most importantly you should find a good marketer. Like anyhting there is a buch of snake oil being sold in marketing expertise and ability. I wrote up these points previously for what I've found as a marketer finding/actuating good people;
1) Look for someone that has experience working big and small companies. Big brands will train comms, project management, procedure and how to think at scale. Small brands give the 'getting it done' skills, generalist experience and show they can get technical/dirty hands. Larger brand experience typically looks more impressive but often work has been project management for agencies and doesnt suit hands on efforts or creativity. Likewise if you're business is big enough to run agencies if someone has always been hands on they often struggle as project managers and understanding how to communicate needs in a way that translates well downstream.
2) Dig into exact contributions for past roles. Ask for logic that lead to decisions. Often marketers talk about great campaigns results but really they were a body in a room with little input. Dig for detail and motivations to decisions and you will find out who is who.
3) Look for initiative with intelligence. Many solid looking marketeers repeat what is always done, optimising here and there. That suits some roles and businesses. There's an unrecognised value in the solid citizen employee. But for smaller business looking for exceptional results you need someone who will see the world independently of the current enviroment. This is someone that will deliver results vs turn wheels for the sake of it. Ensure they have this ability to spot entirely new oppurtunity and deliver on it.
4) Experience counts. It's easy to be attracted to enthusuasm but confidence/enthusiasm and ability are often confused. Look for someone that has done things. When looking at people with higher level expereince ensure they can get thier hands dirty. Make sure they have the ability to learn and adapt vs puely strategise.
5) Don't go cheap. I often see startups advertising low paid roles a couple years experience, while they pay for experienced developers. Half the price sounds great but they will bring a fraction of the value.
6) Find someone that can analyse data vs report it. There's a big difference in the 2 and the former is surprisingly rare.
7) Avoid anyone that shows narcissistic tendency or is generally 'me' focused. This personality tends to be bad comms people (especially with social) as they see the world from their POV, not the customers. Also your risking a tough working enviroment. Look for things like how they delivered on a job they felt was wrong or lacked value as well as the usual egocentric viewpoints when they discuss marketing examples.
8) Look for someone that lives marketing beyond thier job. A person that can talk about companies beyond their own and has interest in the wider industry and technologies vs focusing only on thier job.
9) Dont stress about direct inductry experience. Unless there is incredibly niche market knowedge or contacts needed a good marketer will be good regardless of product.
10) Sales and marketing are not the same thing. Know what you need. They dont often come all-in-one.
11) While not an absolute I usually check linkedin contacts to skill endorsements ratio. Typically this ratio is higher for the people I know are good marketers. I wouldn't make my decision by this but is seems one of those soft indicators.
12) When you interview give a 10min exercise before to discuss and cover up real-time actual skills. E.g. show them some relevant to role campaign materials (e.g. landing pages/EDM's) and ask them how they would improve. Ask them what they would do with $50k. Typically I add in some spelling/grammar mistakes to also look for attention to detail as it tends to be a 'you have it or you dont' skill (like initiative) and not something you can train up.
Once onboard;
13) Give marketers product input. They should have their finger on the customer pulse and valuable views on what sell/motivates users. Dont let tech side shut out marketing.
14) Make sure they have a budget. This goes well with the above point. Generally I'd say a 10-20x marketing salary would be a good rule of spend if bringing a permanent marketing role in.
...hope that's useful...