Are you an Instagram user? More than 100 million of us are, which is why Facebook (META) appears to be moving quickly to bring ads to the photo-sharing site even as Yahoo! (NASDAQ: YHOO) takes steps to upgrade its competing service, Flickr.

Flickr is the better service, says Tim Beyers of Motley Fool Rule Breakers and Motley Fool Supernova in the following video. Why? Desktop integration. Instagram so heavily favors its mobile apps that -- unlike Flickr -- desktop functionality is muted, at best.

The Instagram-vs.-Flickr debate matters, Tim says, because both services are potential catalysts for their parent stocks. Right now, Yahoo! and Flickr appear to be better positioned, but it's also early in the transition to mobile-first computing. Facebook may not need Instagram to profit from the shift.

Do you agree? Please watch the video to get Tim's full take, and then let us know where you stand on Facebook and Yahoo! at current prices.