1. They are free. If we are talking about business, we should know profit is made when you deduct costs from the revenue. If the costs are zero, one part of equation is optimized already. So you have more time to concentrate to the other half: the revenue.
2. Weebly is popular. It is among top 500 most visited sites on the internet. With more than 10 millions of sites hosted under that domain it is roughly the same rank as Squidoo or HubPages. This still doesn't guarantee it will be up 100 percent of time or search engines will index your site on Weebly fast (or at all) but it certainly offers good chances for that. In 2007 it was declared as one of top 50 sites in the world by choice of Times' editors. This means quality and calculating in web years there is tradition too!
3. Weebly sites are really easy to made. They are based on drag and drop concept of modules and there are tons of free already made designs available.
You don't need any HTML knowledge to set a site on Weebly but if you got any, you can use it to your full advance.
Did I mention there are many free tutorials for absolute beginners and for experienced users available?
4. It has a lot of features even in its basic form: you can use text, pictures, galleries, slideshows... It also includes contact forms, audio and video players and you can also add files to download. Weebly can be used as static site or blog or combination of both.