Upselling is a sales technique where the salesperson encourages a more expensive purchase by a customer by persuading them to get an upgraded version of an item or to purchase add-ons. Remember our food processor example? That food processor could probably be best used with a book of recipes, which also can be purchased at the same company’s website.
If you have pop-ups and optins on every page, I would have to think that it would be a lot harder to convince someone to link to it. Especially since the pages where you have your optins (and probably receive the most traffic) are probably the same pages that you have your best content on as well that you'd be hoping to pitch in your outreach campaign.