I got involved with a marketing organisation a while back professionally, who had interesting things to say about new product launches. They knew their stuff; below is my attempt to convert what they said to blurbs.
Current marketing thought looks to divide up a potential audience into their behavioural groups and market the product to the groups, with an emphasis on the things they desire. Note, what group a person will belong to will change over time as they become more familiar with the product on offer / approach the product again.
I would suggest that for con role-playing games there are four groups:
Let me deal with the first and fourth as they are the simplest.
Will always play. There's a word on the blurb that catches their attention and they sign up based on that. “I'll always play an X” (Joe Blogs game, Amber game, Freeform etc). There's very little need to market to this group. Once you have the word they seek on the blurb, they’re in.
They are however, good guys to get as they will (assuming you deliver a good game), advocate the game to others “That was brilliant, you should play X”
Are highly unlikely to play. Again, there's a word on the blurb which completely turns them off. “I'll never play a Y” (Joe Blogs game, Amber game, Freeform etc). Again, there's very little need to market to this group. They simply don't like what you are offering. Now that's not to say that they won't sign up, but it won't be your marketing that does it – “Please, team member, we need to be a full team to play this comedy game. Sign up for us?”. Once they do sign up, should you deliver a good game, they may turn into a different category next time. But they have this opinion for a reason and it's unlikely to turn around with one good game.
I would suggest the needs of these groups are simple. Explicitly state what the game is about – provide the word that will make them sign up or not.
Firstly, these are either people who have never player your game before, or who have had bad experiences with your games/genre/style of play in the past, but are willing to give it another try.
Yes, we have finally gotten to a group who may read the blurb. It will certainly influence their decision, but I believe their main issue is whether you can convince them this is a safe bet.
You need to convince them of two things. Firstly, that you are ok as a writer / GM. Secondly, that the game is also ok.
For the first, perhaps they need something that informs people of your credentials? X won the best new writer award, Y has been writing for 10 years now, Z wrote the very successful game 1. Would you prefer to play a new game from someone who you knew had some cred? I would.
For the second, I'm going to trial a review of my previous games on the blog to see whether that would help.
These guys know you, know the style of game you write. They are the ones who will scrutinise your blurb. They need to see that this game is cool. Something on the bios might help influence their decision, butI think the game will dominate.
This is where you need to make sure the pop and the fizz of your game is clearly demonstrated in your blurb. This is a "show, don't tell" type of situation. Show the hooks, the excitement. There's something in your game that inspires you - write that bit down. Or pretend you are talking to your best friend about the game. Write the snazzy bits of your conversation down.
At a practical level
The thing closest to con role-playing games I can think of is a restaurant cafe menu. You have to make your choice without seeing or interacting with it. You go to the restaurant based on your past experiences. You need to be sold on each new dish and they have a variety of different ways to put together ingredients to make a meal.
So, how do restaurants sell dishes? They describe them.
The tag line for my game from Phenomenon 2009, Poppa, would then become:
A collaborative, 5 player game about politics, lying on a bed of family tensions.