Multi-vendor marketplaces, like ThemeForest, can be very successful. Chose a niche and create a vendor website for it. Your marketplace could be anything, from a platform for local artists to sell their work on, to an online digital product store. Once set up, invite people in that industry to sell their products on your site. You take a percentage of their profits when items sell.
Again, if your blog has a large reader base, then businesses may be interested in paying you to review their services or products. Not only will you get a free trial using whatever these businesses are selling, you will also get a fee for writing them a review and posting it to your site. Paid reviews (and other paid and sponsored content) can be big money, so advertise this service on your contact page to generate business.
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.