A rule of thumb for weirdness in age difference is age/2+7, leaving you at 51/2+7=32,5. So going by that, 30 is a bit on the young side, which is obvious also from the fact that you felt the need to create this thread.
If one person would be in a position to judge you for it (or rightfully feel weird about it) it’s your daughter. It’s safe to say she seems cool with it, so whatever.
Not strictly a scam, but there’s a little money to be made creating viral content on Facebook. They receive a tiny portion of the ad revenue from Facebook when they generate engagement.
It’s just Facebook sucking really.