Internet ads give you a subject line of four or more words. This means your headline has to get the prospect's attention and tell them what your ad is about. Pack as much key information as you can into just a few words. For example, if I'm selling a computer, my headline would vary depending on the audience. Keep the body of your ad short.
Shorter ads cost less.
Even if you can stretch out with a 50 or 100 word ad, make your writing concise. There's no need to write in complete sentences in classified ads. Lay out the essential information on your product or service, show the prospect how it benefits them, and give your contact info. You're poking your money down the drain if you don't know which ads are working and which aren't. Key your ads when you can.