Yup, the number of anonymous questions is becoming a bit of an issue - but as Arthur said, we're working on plans to fix that.
It seems that people seem more than happy to ask a question, but are either struggling or hesitating to sign up.
The dreaded "social signup" could be behind that, but also more simple and reassuring copy in that asking process could help to.
At the moment, once a question has been asked by a newcomer, they will be asked to categorize it:
Then they are asked to sign up to receive notifications when their question gets an answer.
It seems that this last step is too daunting for roughly 90% of askers, resulting in a whole lot of anonymous questions.
There are other issues that need addressing too. Even the people that do sign up aren't always as active as we'd like, so we're working on ways to make that happen too.
You should really join our Blurtit Facebook group here: https://www.facebook.com/groups/587600777974843/
We're discussing and coming up with solutions to exactly problems like this, so it'd be great to have your input!