I work in a digital agency serving corporate clients. We have build Costlocker (https://costlocker.com) a tool for monitoring our project costs and profitability.
We desperately looked for such tool to use it ourselves, but found nothing. So we decided to build it. Only in the process of making it, we have realised that there must be other agencies that need it too.
In the end we have a product that we use ourselves everyday and sell it to other agencies too. What's interesting, we are still learning how to use it in the best way possible and we then share our knowledge with other users. So the benefit of using the product yourself is not only in requirements specification and testing, but in workflow and usage best–practices.
We desperately looked for such tool to use it ourselves, but found nothing. So we decided to build it. Only in the process of making it, we have realised that there must be other agencies that need it too.
In the end we have a product that we use ourselves everyday and sell it to other agencies too. What's interesting, we are still learning how to use it in the best way possible and we then share our knowledge with other users. So the benefit of using the product yourself is not only in requirements specification and testing, but in workflow and usage best–practices.