I was thinking of something just like this about a week ago, and I actually mentioned it on a thread and why exactly it wouldn't work. This is the principal issue that post-based automatic campaigns have: spam. It's very simple. That's why signature campaign managers exist, they check quality, etc. If your counter-argument to that is "someone can just check for quality every once in a while", then your bot is useless regardless.
Making a crawler for that isn't hard, it's just a bad idea.
Spam is and will always be a problem, not only for posting in forums, but ad clicking, surfing, email and even if you are handling folders in the streets, but the point is, the better you can manage, better will be your campaign...
But a crawler is going to save you next to no time. Campaign managers will still have to check for spam - that takes a lot of time - and then deduct posts, make payments keeping deductions in mind, perhaps add in bonuses depending on whatever contests they're running...
Basically the crawler is just going to track post count, and that's something that you can do with a calculator by taking the starting post count, ending post count and any deductions in about 10 seconds.
Let me explain better.
Lets say you want to run a signature campaign of post/week.
-First of all you would have a place to publish your campaign and find workers (users), and to do so, you would have deposited the amount you want to spend in that campaign, so the system would also serve as escrow.
-The users would register at the system and they would be allowed to work on your campaign (only one campaign at the time of course).
-The system from time to time, will track that user's profile every hour to make sure the worker didn't changed the signature.
-The system from time to time, will track that user's posts and try to group them as spam or not, and provide statistics for the advertiser and the worker.
-At the end of each payment cycle the system would ask the advertiser to validate the data collected, grouping the posts that are definitely spam(equal posts), and flag as "probably" spam the posts that look alike, so the validation work is minimized.
The system could also make the payouts since we could easily connect it to usecryptos api or something...
Like i said, the point is to reduce most of the work of the advertiser and the worker.
Its not possible to avoid all the spamming even if you are a human checking everything, but the better the tool better will be your campaigns...