Hi - I keep seeing a certain font on book covers. It's a bold, caps, very simple, sans serif font with round 'O's and it seems to have different weights. Any ideas what it is? Or is there a standard font that you like to use like this? Any advice appreciated. Thanks!

The first book cover is set in Brandon Grotesque Bold (with lighter weights used for the subtitle and author's name).

The second book cover title/author's name is set in Cera Pro Bold (with lighter weights used for the secondary type).

Both Brandon and Cera would be classified as geometric sans serif typefaces.