While interviewing him on stage at Web Summit in Lisbon, CNN Money senior technology correspondent Laurie Segall asked audience members if they had noticed situations where an ad was served that matched a subject they had recently been discussing with friends or family.
A few audience members waved their hands and Chudnovsky said, "Let me shut this down right here. No we are not using anyone’s microphone to target ads, nor are we using the context of your messenger conversations."
What's happening, he said, is that people are spending more and more time on Facebook and on messenger.
"Given the amount of content you tell your friends and the amount of content you will see in your newsfeed, statistically, a coincidence is likely to happen. It is a human vice to jump straight at this sort of explanation instead of looking at the statistical probability of the occurrence. Now, not everyone has a math background but I can tell you that that statistical probability is high," Chudnovsky said.
But conversations are part of Facebook's strategy for the future with a growing focus on chat bots on its messenger platform.
"I believe that messaging will be a fundamental change in how brands communicate online with consumers in the next decade. There is more and more migration to messaging platforms and we try to be a part of that," Chudnovsky said.
As part of that, Messenger 2.2 which launched yesterday, has a customer chat plug-in that will extend Messenger experiences on to a business's website.
The chat plugin is still in closed beta stage but will let people talk with businesses on their websites and in messenger, and transition back and forth without losing the conversation's history and context.
Beta partners for the update include: Air France, Argos, Aviva, KLM and Zalando.
"People like to call businesses less and less. It’s not efficient. Do you want to be on hold? Do you want to talk to somebody when you can message as you would to someone else and have a fast answer back?" Chudnovsky asked rhetorically.
Two years ago, Facebook opened Messenger up to businesses and today they have more than 100,000 developers building conversational user interfaces inside Messenger.
What currently works best, he continued, is when bots handle part of the conversation but when it gets into areas that are more complex, it hands it over to a human.
"Those combined experiences are really taking off," he said.