We generally do that for images. We suggest to do the same for typefaces.
When its possible, its better to credit typefaces used in your documents, publications, books, posters, websites. Along your signature in the colophon, it add value to your own work.
Our license say about fonts credits:
The end user of this license agrees to do its best to credit Typofonderie in conformity with the code of intellectual property, and international conventions and to the copyright regulations by indicating: Font software name, © designer name, Typofonderie in the colophon or/ and any place when generally printer name and generals credits appear.