Advertising Westercon 67 through Podcasters

Podcasts...does anyone actually use them? After looking into the podcast audience, the participation is very low and it doesn't seem like podcasters are someone we want to spend time and money advertising on. Podcasts do exist, but I feel like people would be much more responsive to advertisements over the radio or through booths set up at related events. The podcast following is so small that it just doesn’t seem like it’s worth the work that would need to be put into it, and I don’t think the results we would get from advertising through podcasts would be as successful as we’re hoping.

However, although the following isn't as big as some other outlets, there is still a way to advertise to them without going out of our way too much. Here are my ideas:

Tweets:

-Creating your own story isn't as hard as you think! Come to @Westercon67 to learn tips and tricks to improve your skills!

-Do you have great ideas but don't know how to get them down on paper? @Westercon67 is here to help! Come learn how to be a better writer!

-Your fantasy story can be a reality...@Westercon67 will improve your writing skills one workshop at a time!

-Podcasts don't have to be strictly online! Come to @Westercon67 to meet fellow podcasters and gain tips to improve your writing!

-You've heard the podcasts...now it's time to start your own! @Westercon67 will teach you how to write your very own podcasts!

-Don't just be a listener, be a creator! @Westercon67 is here to improve your writing skills!

-You've talked the talk, now it's time to walk the walk. Come to @Westercon67 to learn how to create your own stories!

-That brilliant idea of yours doesn't have to stay cooped up in your brain any longer...come to @Westercon67 to become a better writer!

-Are you up to date on the latest podcasts? Come interact with other podcasters at @Westercon67!

-It's time to act on your instincts and produce your own podcasts! Come to @Westercon67 to learn how.

FB Posts:

-Now that you've heard the different podcasts, it's time to create your own! Westercon 67 will teach you writing skills and give you the motivation to become a creator! 

-Love interacting with podcasters online? Why not make those online friendships a reality? Come to Westercon 67 this July and meet other podcasters just like you!

-Being a writer isn't as hard as you think. Come get started and learn new skills at Westercon 67 this July!

-Do you have a prize-winning story idea stuck inside your head? It's time to get those creative juices flowing! Visit Westercon 67 and sign up to attend this July!

-You've been a fan long enough...it's time to be the creator! Come to Westercon 67 to learn tips and tricks to become a better writer.

EDIT:

Here's my spreadsheet (finally!)

Keyword	Total Pages	Avg. Monthly Searches	Pages per Search	Competition
writing workshop	62,000,000	1,600	38,750	Medium
creative writing exercises	11,500,000	3,600	3,194	Medium
writing prompts	16,100,000	40,500	397	Low
creative writing ideas	101,000,000	1,300	77,692	Low
writing tips	352,000,000	3,600	97,777	Low
writing practice	649,000,000	1,000	649,000	Medium
creative writing workshops	14,900,000	210	70,952	High