This was great! You’re right, there are sooooo many ways to be persuasive. One thing that I do (when it fits) is to take a subject or idea that I’m attempting to share and dramatize it. Exaggerate it. It helps to get a point across. For example, a friend of mine just wrote a great radio ad for a business that wanted to let everyone know of ALL their many services. Which is no easy feat if you’re trying to stay away from being boring. So, he wrote an ad for the business as if you were ordering their services at a drive-thru fast food joint. This particular concept also would fit into your “Comparison” tip.
I think you might find this topic a little bit limiting because there aren’t very many reasons *not* to spay or neuter a pet. It’s not a debatable topic for most reasonable pet owners–the answer to topic 1, for most people, is a simple “yes.”. If your goal is to be debatable, you could push this topic even further by arguing that pet owners should be required to pay fines if they choose not to spay/neuter a pet (unless they’ve applied for a breeder’s permit or something). That’s one idea.