Law firms are already ranked on a variety of criteria such as profitability, prestige, and diversity. From the client standpoint, these ratings are helpful, but not necessarily essential. Now, for the first time, firms are going to be rated on something that really matters to the companies that hire them: customer satisfaction.

On Tuesday, the Association of Corporate Counsel will launch what it calls the ACC Value Index. According to a press release from the group, the index “will allow members of ACC to share ratings of law firms based on client satisfaction so that they can better meet company demands.”