Honest question, can you upload a script file (PHP/Perl/Python/ASP/Whatever) to tumblr and integrate it with other parts?
When I was freelancing I used to get a lot of requests like this: I want blog/comments/sharing, image gallery, video, and --insert business specific thing here--.
And Wordpress and its plugins make this easy(ier).
No server-side code allowed, but you can work all the jquery magic you want and they have a facility for static pages with arbitrary URLs. I'd probably not recommend selling it to a business, because, for example, here's how I'd do an image gallery:
1) upload the pics to flickr
2) use jquery to grab the pics
3) make a static page to display them
Also, because it's clear that their service is designed for single-person blogs, their group blogs have some annoyances that range from minor to severe.
When I was freelancing I used to get a lot of requests like this: I want blog/comments/sharing, image gallery, video, and --insert business specific thing here--.
And Wordpress and its plugins make this easy(ier).