No, I have always had superb results with inexspensive seeds. I think it's a matter of time. Give them a few more days.

What trudi said. I've sown plenty of these seeds and they germinate well. If the petunia seeds were pelletized, i think it may take a litle longer for the coating to dissolve for the seed to sprout. Don't give up!

yep those coated seeds just prevent good germination even if they are helpful to handle seeds. No expert here on petunias but it took longer than marigolds to sprout and they stay tiny longer too.

Last year I put out american seed petunias on April 25th and they didn't germinate till May 21. Worth the wait though cause they put on the best show I've ever had with petunias.
sowed petunias on April 24th this year and just patiently waiting for them to germinate.

Fran