Bob Fernandez reports for Philly.com:

Comcast Corp.’s deal to market Sunrun Inc.’s solar roofs to its cable and internet customers could lead the Philadelphia-based giant to take a stake in the San Francisco company if the arrangement generates enough new customers.

Comcast’s marketing for Sunrun — which will launch this year — will be through online banner ads, bill inserts, and direct mail to subscribers. Subscribers would have to contact Sunrun and would not be upsold on the phone for solar roofs when they call Comcast for repairs or questions about Xfinity cable or internet services, spokeswoman Jennifer Moyer said Friday.

With the pact, Comcast, which has 29 million customers, can realize a 5 percent equity stake if the agreement leads to 30,000 new customers for Sunrun or Comcast spends $10 million on marketing the program, according to the agreement filed with the U.S. Securities and Exchange Commission. Comcast will take up to a 10 percent stake in the company if its marketing leads to 60,000 new residential or commercial customers over the 40-month term of the deal.

Sunrun’s stock on the Nasdaq market soared by as much as 10 percent Thursday when the deal was announced, but then fell by almost the same amount Friday to a market capitalization of $738 million. Sunrun posted revenues of $453.9 million and a net loss of $303 million in 2016.