Salesforce’s acquisition of ExactTarget in 2013 was a slap in the face to HubSpot, and since then Salesforce has aggressively grown its marketing cloud.

HubSpot, for its part, introduced its own sales CRM solution and went public in 2014. As a result, the two now compete in a number of ways.

But it wasn’t always like this.

In 2011, Salesforce was an investor in HubSpot. And HubSpot remains one of the most popular apps on the Salesforce AppExchange, with 576 reviews and 4.6 stars.

Today the two have put away their differences to extend their partnership for another five years. HubSpot will continue to offer integration of Salesforce’s CRM into its inbound marketing software platform, and Salesforce will continue to list HubSpot’s software in its AppExchange.

Brian Halligan, HubSpot’s CEO, told me that about 20 percent of HubSpot customers also use Salesforce CRM. Joint customers have been asking about the future relationship between the two.

Halligan admitted that the companies have become somewhat competitive, “but rather than limit choice for customers, we opted to put aside rivalry and do best by our customers.”

HubSpot customers will continue to have a choice for CRM. Bigger customers are more likely to use Salesforce, while smaller ones may opt for HubSpot’s newer and lighter-weight solution.

“I tip my hat to Salesforce for doing this,” said Halligan. “It’s choice for customers through ‘coopetition.'”

As we found in our own research, marketing automation is growing fast and delivering outsized ROI. But adoption remains low, and so a large opportunity remains. In short, there is room in the market for both Salesforce and HubSpot — at least for now.