This is a pretty open field but things that should be considered while creating the designs:
I intend to use this design on multiple mediums (print, embroidery, etc) so no transparent gradients please.
I prefer clean, uncluttered design, logos I tend to appreciate the most make excellent use of negative space and the more clever the mark (takes a second glance to 'see' it) the better.
Use of a fun/modern color palette (within reason as this is meant to appeal to both male/female consumers as well as business owners) is recommended as this will also likely determine the color palette for the entire brand.
I don't think an illustration-heavy mark is required as much as well thought-out font, color, and overall design. However, I have an image in my head about using the '.' to indicate that you frequent a business.
Theoretically it could be something as simple as Foursquare or Facebook, but something that lends itself to smaller versions or a memorable iconic version will be highly considered.