I just signed up for OLD as well. I agree with everyone else. Humor helps so much. Maybe add a sentence of what types of books you enjoy. I always take note of that and if a guy reads similar books that I do, it makes for easy conversation and I take note.
But I do think it’s a numbers game. Are you writing to women? When you write to them are you making it known that you read their profile? I get that you might not get back a response. But how long does it take to read a profile? 45 seconds? To write a message? 2 minutes? That’s not much of an investment. Just make sure your messages aren’t generic “hi how are you” or “great profile and great pics”. Someone posted something they obviously cut and pasted and reuse over and over that tells me about them (like another profile) and then they write “tag. Your it” meaning, I’m supposed to respond. The guys I feel safer about responding to are the ones that brought up something I wrote about.