I've been seeing a lot of gig posters ending up on picture feeds, most notably fffound. They tend to scrape the TITLE (ie. the part that appears in the title bar of your web browser) as well and I see that GP currently provides the band names there when viewing a poster.
It would be cool if the designer's name could be added as well as this might help people who are trying to find the designer.
fffound links back to GP so people who do click on the posters can figure it out, but just in case there's a feed out there that doesn't, it might help.