Since your pin is going directly to a seller’s site and not your blog or review, make sure that the title and description of each pin is informative and straight to the point. You can use two to three sentences and always, always, always disclose. Remember that these titles and descriptions are what help Pinterest users find you when they do a search. The better your description is, the more sales you will get.
One other positive about the Ultimate Bundles affiliate program that your readers may not have realized… They actually offer second-tier commissions too, meaning you’ll earn a share of the sales from any affiliates that you refer to the program. In this case, it’s 10% of their bundle sales during their first year as an affiliate which could be a nice earner!