I don't do it as much nowadays but I was a horny 20 something living on his own at the time of Craigslist being popular. I consider myself orally bi. I only give blowjobs or receive them, and I rarely receive them. I prefer straight, bi or married guys. CL was kinda a perfect storm. Guys would get on for whatever and notice personal ads and I think the realization of what could happen came in and some went for it.
I remember being really surprised at how many straight and married guys were on CL. But then I thought they'd be more discrete and possibly more safe. Also, I'd actually already sucked my first. He wanted to touch me and play with my dick, just things I wasn't interested in. He kept insisting and made me cum while jerking me. I lost interest and left. I figured a straight guy would let me just sit between his legs and suck. That's all I really wanted, and if I wanted a guy to blow me that's how I would want it. Maybe have some porn on as well.
When I finally put an ad up there were so many responses. I didn't really know how it worked and just emailed back and forth. As the emails would get closer to us meeting I'd get nervous and back out or disappear. I was and am a bit shy so I had to work thru that. I put up a few ads before I got comfortable enough with anyone.