Backstory: As you know, we're a small marketing/dev agency based in Baltimore, often times we leverage friends, fiverr and other freelancers for sales copy edits. We would 100% pay for someone to be on stand by for up to x word per month sales copy.
The Idea: Much like DesignPickle, offer a similar experience for copywriting.
Deep Dive: Having a consistent feel for your sales copy is a key component in marketing. Without paying for a full-time copywriter, an on-staff small team of people who charge by the word could help augment existing small businesses.
Validation: We would pay for this and there are already freelancer copywriters who charge by in chunks of words at fiverr.
Monetization: Piggy back off DesignPickle's success and set a flat rate per month. As with gym memberships I'm sure there's a lot of profit where clients don't fully take advantage of the full service.