According to Google it does:
-
Appear on the second visit:
The user has visited your site at least twice, with at least five minutes between visits. -
If the user dismiss the banner it never comes back:
If a user dismisses the banner, will it appear again? No. Not unless the user clears their history. We want to make sure users have a good experience. We will likely be changing all the heuristics over time.
The implementation can get better, we can defer the banner till we feel like.
Also, we can log Dismiss and Accept to make some stats.