It seems sensible to assume it helps them for something otherwise why bother developing and releasing it? I also don't think it's a matter of bottleneck - if you make the front-end php run faster you need fewer servers, fewer servers/user, more money. This has come up in discussions about google as well - there are some scales at which even comparatively modest improvements in efficiency count. It probably won't make a world of difference to My Cousin's Personal Basement URL Shortener.