There is certainly a space for advertising. Off the bat, a brand could use nostr:nprofile1qyjhwumn8ghj7cn40faxymm594ex2mrp0yhxyatvd35hx6rzda6kuare9e3k7mgprfmhxue69uhkummnw3ezuum4v3hkxctjd3hhxtnrdaksqgxfax7upvpuyx7nx7sjmn6mgc75nld0azz25y4mj5xpst57fklfhqy6fmt5 with a large bounty to solicit engaging content about a product. I'm sure some solution could be made where a rebate could be advertised and redeemed out over Nostr as well...