I have several instructional screencasts that I want to put on my web app. My web app charges money to users. I am wondering if YouTube is ok with users uploading these types of videos (how-to video but for a company trying to make money) on their site.
This would seem to be the relevant point from their terms of service:
E. you agree not to use the Service (including the YouTube Player) for any of the following commercial uses unless you obtain YouTube's prior written approval:
i. the sale of access to the Service
ii. the sale of advertising, sponsorships or promotions placed on or within the Service, or Content;
iii. the sale of advertising, sponsorships or promotions on any page of an ad-enabled blog or website containing Content delivered via the Service unless other material not obtained from YouTube appears on the same page and is of sufficient value to be the basis for such sales
So as long as you aren't charging your users to access the videos and not selling advertising on the videos you should be OK. However, as you are charging for access to your web application this could be construed as charging for access to the videos.
However, I'm not a lawyer so your best bet would be to contact them and ask them if it's OK.