Good pint about the pic. OKTrends has a really interesting study of which pix get the best results, it can be surprising. I'm on OKC just for the hell of out and I ignore almost all messages I get. This sounds stalk-y and weird, but... I actually think I might be more likely to pay attention if a guy sent me a polite follow-up message a week or a couple days later even if I hadn't replied the first time.
It's probably best to acknowledge up front that he will almost certainly have a harder time than you. It's tough for adult men in the dating world. If you agree that that's ok up front, maybe it will prevent some jealousy or frustration if/when you end up with a partner before he does.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.