You can be an Agile Marketer without applying any Agile Methodology. Ask questions:

Some Marketers: We’re going to do some direct marketing, a webinar, distribute some flyers.

Me: Great! Which channel works best?

Marketers: What do you mean? We use the channels we’ve always used.

Me: Well if you don’t know what’s working for you, how do you know where best to spend your money?

Me: How many webinars did you do last year?

Marketers: 7

Me: How many do each cost? How many leads, how many conversions?

Try something different.

Other Agile options

Do X. Try some options, if it works, great, if not try something else.