The reason they race around on release day is so that their firm can get to the 'client' first and thus take the commission that comes with the job. It's a highly competitive business.
I would imagine they spend the rest of their time chasing around the various sets of records trying to locate people or are following up more difficult leads. I know just from doing family history research that you can spend a whole day on the internet and be lucky to come up with one name at the end of it.