When should you cross-sell?

Probably later than you think

I get it, the cross-sell is tempting. You’ve already done the work to acquire the customer, you have a great sense of what they need—why shouldn’t they buy it from you?

Here’s why you should probably wait:

1. It's not going to move the revenue needle for you much in the early days—your total customer count is small, and only a fraction of your customers will buy your new cross-sell.
   
   As an example, when I last looked, only 60% of our bookkeeping customers buy tax from us. Which is actually a pretty wild stat—they are essentially legally required to buy it, and almost half of them don't buy it from us, even though we're already doing their bookkeeping.
   

2. It's a distraction. Unless you're Parker Conrad, you probably should keep the main thing the main thing.
   

3. It'll always be higher-ROI to do later. See #1: the cross-sell's total value to you is basically customer count * attach rate * ARPU, and presumably if you just wait, this number will go up—because customer count is going up.

Basically, your time is probably better spent focused on growth or retention, rather than on maximizing revenue per user.

When is this not true? When should you pursue the cross-sell?

The biggest case that makes this not true is when the cross-sell helps sell the main product. We only started selling tax because we found that some percentage of people would not buy bookkeeping from us if we didn't do tax—they'd just go somewhere else that did. (If the cross-sell helps retention, the same argument applies.)