They accept everything from Twabbles (tales told in exactly 100 characters) and Drabbles (up to 100 words) to short stories of up to 2,500 words. They also accept poetry of up to 1,000 words. Payment is for stories of 500-2,500 words only.
Manuscripts are accepted throughout the year; their self-reported response time is three to four months. According to Duotrope, the average response time is around two months. The Drabblecast does accept simultaneous submissions, but ask they that you let them know immediately if your piece gets picked up elsewhere. From their Guidelines page:
Here’s my advice- Listen to a few stories first.
There’s something specific we are looking for here- that weird idea you have, that hilarious or disturbing scenario you’ve been brooding over.
DC likes speculative fiction stories that are humorous, bizarre, gross, disturbing, badass, interesting and original. Stories thick with vulgar language and/or sexual situations stand less of a chance of being accepted. But ya never know.