Yes, that's a good thing to do...But if this is all an integrator is doing, he's still missing the mark...Those sorts of things when we say them at the end of an installation sound like this...

blah blah blah...

Sure, you'll get one or two here and there...But still not a steady stream of referral work.  You can't tell your wife, kids, or your dog to do something one time and have them do it....How can we expect a stranger to go out of their way and sell "us" to someone?  We can't.  We need to take additional steps to get referrals.

And that's where most guys are failing, because they're not contacting their customers after the installation...Think of something like this...

1.  Mention "I need referrals"  at the end of the installation...Do this while they're giving you a 5 star review on Google. (While you're standing in front of them).

2.  Call 4-7 days later to thank the customer for the business, to check in to see if they have any additional questions or concerns....Tell them you need referrals again...

3.  2 weeks after installation, they receive an email (because you have enough sense to get their email address)...Telling them that you NEED referrals and offering some sort of an incentive if their referral "pans out"...Maybe a 1 yr. NETFLIX subscription, a Dinner giftcard,  Sonos Play1....whatever...anything that incentivizes them to refer you.

They need to be told over and over...at a minimum of 3 times before it even sinks in that you want referrals.