WEEconomist is giving good advice. You don't want to post a very early draft paper, but you need to show that you've really got a paper in progress. Slides are a good way to do that, with a note on an early slide that the draft is not ready yet. Also, it's a good discipline to make slides even for a work in progress, even if you don't ever use them for a presentation, because it orgnizes your thoughts and makes you look at it like an outsider would.