Adding breadcrumbs can be very beneficial to your website, especially if it’s an eCommerce one. This is due to the fact that they create structure within your site.
Most, if not all on-line stores, link their products from their category pages. This means that the category pages send some equity to the product pages, making them stronger. Not a bad thing, overall.
However, I’m pretty sure though that you want your category pages to rank high, because those are the ones optimized for the keywords with the most search volume. With Breadcrumbs, you will consolidate the strength of your Category pages by linking to them with all your subcategories and related products.
If you’re using a CMS, things are pretty easy. Most templates already come with breadcrumbs, so make sure you check the template’s settings first. If not, you can search the web for “Your CMS Platform” + “breadcrumbs plugin/extension/module”. I’m sure there’s something out there for you.