I replied to a few posts but I never got any responses?
Sometimes emails end up in people's spam or junk mail folders so make sure you check your spam or junk mail folders for replies (sadly it's impossible to know if an email ends up in a recipients spam or junk mail folder). And it never hurts to resend an email if you don't hear back within a day or two.
Other times, you won't receive responses because people forget to mark their offers as taken. This causes their offers to stay on the group when they should have been removed. To help prevent this, posts are automatically removed from the listings after 30 days.
This can also happen when someone posts a popular item that causes them to get a lot of replies. Rather than reply to everyone, people often only reply to the person they choose to gift the item to.
And a lot of posts get claimed within a few hours or days of being posted. So you're more likely to get a response if you reply soon after a post is published.