Fan Landers: My Excellent Band Knows Jack About Marketing. Help!
Anyhow. You need to redouble your efforts. Network with other bands that are in and out of your scene, pass your album to national and regional touring bands at the merch table after they play, introduce yourself to the promoter at the club you want to play -- just like every other band does. Also, make sure you're connecting with your fans -- have an email list people can sign up for at shows, get a Facebook page and a Twitter account -- so they know when you are playing. Invest in a good tape/staple gun and flier the living shit out of your shows. Promoters love a band that makes their job that much easier. Play some college house parties or campus bars -- your band has that kind of sound that people love when they're wasted. Court a demographic! There is no shame in that.
Showcases are fine, but half the time you are playing for all the members of the other bands and those folks are in the same boat as you. How about putting together a decent bill yourself someplace weird and making it "fun"? Take matters into your own hands and do some rad bill at the janky Chinese buffet restaurant in the basement of the student union and have a piñata? Do a renegade 20-minute set in a gazebo in the park. Make your band an exciting secret to get into and foster some word of mouth. Shape your own destiny. And if it doesn't work, at least you have more fun than playing a showcase that lasts 10 hours in some dank dark bar.
Also, a final thought: make sure the aesthetic of your posters/stickers/promo photo/album art match up with your sound. Judging entirely by your album art work I thought you were going to sound like the Postal Service, not a band that has a song about a woman turning you on by shaking her ass in tight leather pants.
Best of luck,