Printed On Envelope 'Full Postage Paid'

Am I correct in my supposition that the printed 'Full Postage Paid' on this circular is due to the bulk of its original contents? The distressed sides of the envelope seem to indicate a large number of contents, and perhaps the printing was used to dissuade postal employees from assessing postage due?

I think the double oval is of NYC origin but would appreciate a correction there as well.

The postmark appears to be:
FLUSHING / N.Y.

3rd class at rate of 1 cent per 2 ounces.

The text printed by the sender would mean nothing official to the USPOD, they could check it if they wanted to. Is there a return address on the back?

Thanks, John. The stamp (Scott 525) was issued in 1918 helping to date this cover, when that one-cent printed matter rate was in effect.

Verso has no markings nor a return address.

And Flushing, Queens it is!

"Full postage paid" could also have been a clever marketing device. Don't forget what was going on in Nov 2 1917 to June 30 1919, the 1c war tax folks were used to on most mail.

Oddly enough, the 3rd class rate (not over 8 ozs.) was unaffected. (But 4th class, Parcel Post got war-related hikes too.)
In one sense, the mark subtly reassures recipient "we're not trying to do anything underhanded here..." if recipients might have recalled getting circulars mail prior to war rates, also at 1c, and wonder why this mailing was still 1c, etc.