Based on the ship-to info, she is in Jackson, OH. Population 6184.
$75 is pretty cheap, but the in-person exposure is worth $0, so what she is really selling is her ability to promote you online.
It's a novel idea, but really not terribly innovative, although I give her credit for making herself a business in a town that probably doesn't have a ton of employment opportunities for her. The hardest thing for her to overcome will be the fact that people tend to tune out paid shills like this.
She would be better off building up an online persona and name and then more gradually easing into this. OR, make the site "gangofgirlsinyourshirt.com". Sign up franchisees at top colleges across the US, and for $1000/day 50 hot girls promote your brand for the day.
She is charging $30/hr, and is also going to tech tradeshows. That too is an interesting angle, although not very unique. I have been to many tradeshows, and have seen a lot of hot-to-semi-hot girls walking around clad in various T-shirts.
If your target market is mid-20's guys, I think this angle could have some merit. If your target market is the "average" consumer or corporation, I'm not sure how much marketshare you are really going to get from a pair of tits or an ass logo.
I think the real angle for these girls is to do a "Social Media Starter Kit". This T-Shirt girl would be better off not just "mentioning" the product and flickr and twitter, but setting up accounts for these companies and "seeding" the social media sites, then handing the keys over with a bit of training to the organizations. Basically teach the companies that want to leverage social media but don't know where to start how to jump in.
That would likely be a week-long effort, and she could probably charge $3000/wk, based on what I've seen from the current crop of wanna-be SEO hacks.
She would get more recognition in a small town than a big city wearing a shirt (as she will become know for it). No one would pay attention in a big city, but everyone in the small town (and surrounding towns) will pay attention. Living in Ohio I have witnessed the dynamics of word-of-mouth between the two.
Although, the nature of this model seems to leave room for a bunch of different people to do it in different areas/markets. That's kind of neat. If it worked really well, I could see some kind of talent agency trying to organize the efforts--though my gut says that would likely cheapen the effect.
