So why do you keep them waiting at all? Especially if the chance is high that the question is too simple to keep support agents busy with them?
You should always guide your users to the most efficient channel. Not just to make your customers more happy, but also to keep the lines free for those issues that really need attention from an agent.
By adding a small notion of the community to your IVR (where customers select which category their question belongs to) you can decrease the average waiting time and have many happy customers in consequence!
Some examples:
General recommendation (Telco)
Situation: You want to guide all users who are waiting for a free agent to ask their question (or search) on the community.
IVR: As soon as the customer hears the message "there are 3 people waiting in line", ask them: Do you want to get help right-away? Press "#". Then send them a sms with a link to the community:
Recurring issue
Situation: You have a problem where your customers keep on calling about, however with a few quick steps the issue can be resolved. The steps are the same for all users.
IVR: If a customer is selecting the category this question falls into, add a line of text to the IVR: Are you calling about issue X? Then you do not have to wait in line! Check our tutorial on our community, you can find it by searching xxx on Google.
Outage
Situation: Due to a network issue in your data center, many customers cannot connect their devices. Customer support cannot help customers but only log the report.
IVR: As soon as the IVR starts (or if a customer selects an affected category), add a line: Do you currently experience issues connecting xxx? We are aware of the issue, please check on our community for the latest updates. We will communicate there as soon as we have news.
Installation
Situation: A customer is calling your support to get help with setting up the device. The device however can be set up in many different ways, or there are many ways to optimize (e.g. setting up a Sonos speaker for the best sound).
IVR: When a customer selects a category where you know that the community can help better than regular customer support, add a message: If you have a question about the installation of your product, you should have a look on our community. There are many experts who know everything about setting up your xxx.