Let me try to list all of the reasons:
1) When you advertise or tell me that you have a selection of lingerie, it lets me know that you consider yourself a professional professional, which means you want me to appreciate your services enough to become a repeat client.
2) It lets me know that you think in terms of clothes, toys, and other tools of your trade: you'll have covers and lube and you may even have a clean towel to offer me.
3) It lets me know that I'm going to have an experience with a lady who wants to get me in the mood from the very first moment I lay eyes on her.
4) It lets me know that you have at least a basic understanding of how visually oriented men are, and that gives me hope you'll understand other things about the male mind (and other parts, too).
5) It lets me know that since you spent time buying lingerie and bringing it with you, you are likely to be willing to spend the agreed-upon amount of time with me, too. (The kind of person who tries to rush a guy out of the appointment in ten minutes is not likely to consider spending time shopping for lingerie for her clients worthwhile.)
6) It lets me know that you are smart and savvy enough to understand that it helps us both out when you look stunningly sexy. (Hey, you may even manage to get me out the door in ten minutes rather than thirty or sexy.) At least half of good sex is in the head (the big one), right?
7) It lets me know that you care enough to "package" your figure, and that whatever so-called imperfections you may have, you know that I'll be focusing on the sexy camisole and stockings rather than a blemish here or there.
Well, that's just 7 reasons why when you select lingerie it signals to your clients that you're a thoughtful lady and not just a fly-by-night wham-bam-get-outta-here-Sam provider. I can already think of another three reasons and I'm sure there are even more. I look at it this way: When I show up to an appointment with you and you're wearing the lingerie we talked about, the appointment starts off on a high note. But if I show up and you're wearing a sweat shirt and flannel pajama bottoms, that tells me that even though you know I'm going to be bringing a donation for your time, and I could still pivot and leave as soon as I see how little attention you devoted to confecting some "eye candy" for me, you really don't care whether I leave. Or you figure I'm just so hard up (so to speak) for companionship that I'll stick around no matter how you're dressed. Either way, it doesn't bode well for a fun time together.
Thank you for thinking about lingerie. You can be sure that your clients appreciate it.