My prediction is something similar with Twilio + Stripe. If Twilio wasn't already public with a higher mkt cap than Stripe's most recent valuation, I'd guess Stripe acquires Twilio, but as it is not sure. Anyway here's my thinking:

1. Complimentary businesses: Stripe is a developer interface for collecting payments from customers, Twilio is a developer interface for communicating with (and now understanding / "segmenting") your customers.

2. Similar culture: very high emphasis on great DX and developer evangelism. Shoutout to Stripe's docs for being the best in the biz, and Twilio's are not too shabby either.

3. Unique opportunities: Stripe collects payment for their customers, Twilio collects payment from their customers. If everything was under one roof, you could have a situation where Stripe becomes a de-facto bank account. Revenue comes in to your Stripe account and many of your consumables (paying for Twilio's services) could come directly out of that account, removing the need to egress funds to your bank at all, thus reducing financial transaction overhead (which at scale could be a sizeable gain in efficiency).