The burden is on you to convince a potential technical co-founder of value of your skills. Saying "I can do marketing, monetization and bizdev" is vague, therefore unconvincing. Anyone can say that, just like everyone can say that they're a great programmer. The trick is in convincing people you're good at it and that it brings value.
There are 2 ways to do it.
One, you can give examples from the past how your marketing, monetization and bizdev skills contributed to a success of a startup. And talk about specifics, not generalizations. "My bizdev skills increased revenues 2x" is unverifiable generalization. "In a startup offering on-line marketing to restaurant owners I contacted every restaurant in San Francisco and booked 100.000 revenues for our services" is an example of a specific thing that you did, that brought value to a startup and a many people (e.g. me) would not be comfortable doing.
Second is to offer your ideas tailored to a specific person. "So, you're working on startup doing ..., here's a few ideas of things that I could do to get more business for your services".
There are 2 ways to do it.
One, you can give examples from the past how your marketing, monetization and bizdev skills contributed to a success of a startup. And talk about specifics, not generalizations. "My bizdev skills increased revenues 2x" is unverifiable generalization. "In a startup offering on-line marketing to restaurant owners I contacted every restaurant in San Francisco and booked 100.000 revenues for our services" is an example of a specific thing that you did, that brought value to a startup and a many people (e.g. me) would not be comfortable doing.
Second is to offer your ideas tailored to a specific person. "So, you're working on startup doing ..., here's a few ideas of things that I could do to get more business for your services".