Well, being a screenwriter is not necessarily a stable business on of itself. Therefore I would rather go with a one-time payment than staring on their monthly

Well, being a screenwriter is not necessarily a stable business on of itself. Therefore I would rather go with a one-time payment than staring on their monthly expenses horror show. OTOH you will have to support them endlessly, than again, this won't be that much more of a trouble; I am assuming. The general advice is: testing. Drive traffic to your landing pages and see which one converts the best. With that I mean: which source of traffic coverts best AND which landing page design works best. HINT: hire a professional copywriter, he will work wonders for you there. In any case, test and thus find the best performing combo. You should put some effort into the presentation of your company. Why should anyone trust you with their data? This is a very big question, that you MUST address. (Minor nitpick: I've come across websites of small firms and they didn't even bother to tell in which city they reside. This is of course a form of mindlessness, which told me everything I needed to know to not do business with them. Details matter.)