What is an ideal platform or service for collecting ideas & feedback from a large group?

Paperform is my go-to-app for surveys and online forms.

Yep, plus one vote for Paperform!

For Product Hunt we've been using FB Groups for this. Works well because everyone already has Facebook. The posts/threading are easy to follow. And the content that's "most interesting" generally bubbles up to the top of the group.

I've been using Typeform for gathering feedback and ideas from users at Tookapic. It has a free version, but with paid version, you can embed the survey nicely in your website.

Hey Emily, Obviously there's a few options already, but I would wager doopoll would be the leat intrusive and cleanest option to use. Give us a try for free first if you like (up to 50 responses). Available in English, Spanish, French and Welsh too. :)