Intercom invites to refer their tool in their daily recap email

Intercom knows to play their referral game really well. Every day, Intercom sends you a daily recap of what have being the latest signups within your application. An email, that at least in my case, I open everyday. If it’s a such useful for their users, why not to use their users as ‘speakers’ to spread the word about how great is their tool?

Codementor triggers a modal to ask for referrals after each mentor session

Codementor knows that there are more opportunities of having you sharing a referral link either when you are happy with their service, either when you have just spent some of your credit. Or both. After each session you might have with one of their mentors, a modal is triggered after you terminate the session, inviting you to get $25 free if you bring new users. In a similar way, Digital Ocean are doing the same but within their monthly invoices.