Last year, longtime pal and former boss Rusty Coats reminded me of the concept that sales success is algorithmic.

Presuming you're selling a product with any demand whatsoever, a certain number of phone calls will lead to a predictable ratio of appointments, then a certain number of appointments will lead to a predictable ratio of contracts. The more activity, the more you close.

My twin teens extraordinaire, Rachel and Tyler, demonstrated this concept over the past week.

R&T turned 16 in November and promptly secured (a) their driver licenses, and (b) access to an old (pre-recall) Toyota to tool around town — on one condition: Get jobs and help pay for fuel for the hoopty.

So they “tried,” by which I mean they put in maybe five applications apiece to places where they thought their first jobs might suck less than most first teen jobs do. Tyler, the gamer, checked out GameStop. Rachel tried Claire's Boutique and Icing at the mall.

In their defense, the part-time job market remains tough, and adults in some cases take jobs that otherwise might be open to teens in school.

Even so, the twins did not exactly push hard for jobs. They actually believed the managers who told them they would call if any jobs opened up, and keep the applications on file. Like that ever happens to teens looking for part-time work, right?

Weeks passed … Thanksgiving … Christmas … New Year's. I started my new job and an aggressive initial travel schedule, so ol' Dad wasn't much help. Ever-resourceful Ka finally encouraged them to volunteer at the Knox Area Rescue Ministries thrift store, helping check in and stock donated merchandise, until they could find paying gigs. KARM, magnificently, took them on and provided references for their job searches.

And we kept nudging, cajoling, advising, talking about getting jobs.

Last Saturday, we had talked about it enough. I piled R&T into my own hoopty (still disoriented by the fact their car has 40,000 fewer miles on it than mine), and took them to more than 20 storefronts apiece to walk in and ask about jobs.

I gave them specific instructions: Ask for a manager. Look her/him in the eye, and ask if she/he has any openings now or soon for 16-year-olds. Get an application whether the answer is yes or no. Get her/his phone number and full name. And ask when you should call to follow up. Write it all down as you go.

Well, praise be, they wore themselves out but did as I suggested. Then they followed up with the managers who showed interest. My kids got over call reluctance, sold their abilities and found the demand.

By Tuesday night, Rachel closed the deal with Steak'N'Shake, where she started training to work the drive-through. By Wednesday night, Tyler earned his new appointment as a busser at Texas Roadhouse.

So, Rusty, thanks for a lesson I could impress on my kids. More activity leads to more sales. And to gas-and-movies money.