I think this was already his 6th 2nd place of the season. One in San Luis, 2 in Tirreno Adriatico + 2nd in the gc of that race, Omloop and now E3.
I also have to mention that only one of these 2nd places was the outcome of a bunch sprint so although we always talk about how bad his sprints are after a hard race its possible that he just became a by far worse sprinter.
Btw, does anyone know if he will maybe try the Amstel Gold Race this year? I think he should give it a try. Let his teammates attack so he doesnt have to chase anyone, then follow wheels on the Cauberg and then try to outsprint everyone. Matthews did the same last year and almost succeeded and I don't think Matthews is stronger on the Cauberg than Sagan considering that he was the only one who was able to follow Kwiat on the not cobbled "Karnemelkbeekstraat".