And the ads usually work better, the longer they run. The key with using ads is to make your information available in small doses. Write a short ad, and then follow up to responses with a general description of what you're offering. Avoid the temptation to send all your information at once. First of all, it probably won't get read.
People tend to just ignore anything that is very long.
Think about the implications of that when it comes to building a large, duplicating downline. The second, and better, way to market online is to use the online environment to develop relationships. Not commercial relationships, but personal relationships. This is something that is easy to do with email. There's every subject imaginable being discussed on the 'net.