When you configure PDF Stamping for your ebook, once the buyer completes checkout and proceeds to their thank-you page where we present their download links, there may be up to several seconds' delay while our system waits to receive the buyer's info from the payment processor, so we can stamp that info into the copy of your PDF ebook that they will download.
Even after we receive the buyer's data from the payment processor, extremely large/complex PDFs can take longer to stamp than a buyer may be willing to wait, so in that case our thank-you page will eventually give up "stalling for time" before things get too frustrating for the buyer, and it will let them download their file whether the stamping process had finished by then or not. Later downloads on the same link would have the stamp, since by that time the Stamper would have finished stamping the file.
Optimize Your PDF
Our PDF Stamper can have trouble stamping files larger than about 20 MB or so by the time the buyer reaches their download page. See if you have options to "optimize" your PDF for a reduced filesize when you save or export it from the app where you created it. Adobe apps like Acrobat and InDesign usually label this option as "Optimize for Fast Web View" or similar.
Delay the Buyer's First Download Attempt
If you're not able to get the file size under 20 MB, you can still avoid offering the buyer an unstamped file and avoid stalling them after checkout by setting up a Common Thank-you Page URL. Buyers proceeding from checkout would immediately be redirected to that thank-you page on your own site, rather than the E-junkie-generated thank-you page where they could download your ebook right away.
To download their ebook, they would need to wait for the thank-you email we send for each product, which provides a link to reach the E-junkie-generated thank-you page with their actual download link, and by that time the Stamping process should certainly have finished. Make sure you have not disabled the Product Thank-you Email in the settings of each download product. If you have a Common Thank-you Email (all new accounts are given one by default in Seller Admin > Edit Preferences), please see also this page for important tips.