In general, I can happily say that when a business gets my attention it's for a very good reason. The products are yummy, the shopping experience pleasant, and the designer has a great vibe. I also know that most of the time, a review online for a store is a very positive thing with a few minor critiques. These critiques are intended as an advisory for buyers, and a possibility and encouragement for improvement on the designer's behalf.
However, I've found that some things that I thought to be common knowledge about running a business just escape some people. There have been a very large amount of writings about business running tips, but there are obviously some things that have been left out.
Speaking to designers, I think the things I'm about to say just are completely beyond common sense, and yet I found that these things needed to be written.
#1. If your items are not copiable, there is no reason aside from greed or reclusiveness to deny returns or exchanges. Neither of those two traits are likely to make a happy customer. Period.
#2. No avatar shape is the same. If you are making prim clothing pieces that will be attached to an avatar, they should be modifiable, or make a custom fitting available. There are some exceptions (a belly button ring or some shoes might be alright), but for the most part this one is cardinal. Think of it this way... if they fit properly, they look good. If they look good, people want to know where they got it, and more business for you!
#3. If your store has boxes, or items that need to be unpacked, it's polite and good practice to make object entry or object creation possible on your land. That way, the person can unpack and try on an item right there in your store without having to leave. If they like what they see, chances are they might buy something else or another color of it on impulse. If someone has to head home first, chances are they won't be coming back. If you're worried about litter, put an auto return on the parcel.
#4. Make your personal policies or frequently asked questions clear and concisely worded and available in your picks. There are many people who can just barely run SL on their computers, and browsing to your site to find your policies might put a lot of strain on their system, or their will power. Not to mention the simple fact that most people aren't that motivated. If you want someone to read it, make it extremely available (hence, your picks).
#5. When someone IM's you with a clear and polite question, be friendly and approachable. The person is obviously interested in your products, and took the time to teleport to your store location and browse a little. Be grateful for the traffic. If it's a really stupid question with the answers completely surrounding them on a bunch of signs, even then it's possible that the textures didn't rez, and you should answer in as patient a way as possible and encourage them to read signage. Everyone's feelings do matter, and a happy customer is obviously going to be more likely to share their new find with their friends.
#6. If you are very solid and very committed to your policies, or you simply can't do anything about the problem they are having, try to compromise. Maybe offer a discount, give them an item out of your lucky chair (hey it's free anyway). Paranoia is not attractive. There are scammers out there, yes, but for the most part people are genuinely trying to find an equitable arrangement. Giving away items has absolutely no cost to you, and can only result in a more satisfied customer, who, even if they're still sulking about whatever you were not able to give them, will at least not slander your name. Obviously, the desired result is a happy and excited customer who will be delighted to spread your name around and bring more traffic to you. Not to teach a person a lesson, nor to make a point, nor to save yourself pennies.
#7. Make your items clearly labeled with the customer in mind. Alright, maybe SSWZDllDress 0867 makes perfect sense to you, but not everyone is inside your head. If it's labeled something on the vendor/sign/board, label it the same way in the inventory. If it comes in multiple color combinations, make sure the colors are labeled too! There are many simple formulas and ways that other designers work with variations, most of the time going from the most basic first, and then down the line of details "Victorian Top Hat: Black/Black/Copy". First black is the base of the hat, second black the hat band, third the permission. Simple, easy, and if you forget your own arcane organization you can remember it pretty easily again.
I know to any designers reading this, this might seem like the most ridiculously obvious thing in the world. But if you can believe it, I actually had a shopping experience with a designer who violated every... single... one. And I needed a place to just vent, and to rant, and to share it with you because I'm sure everyone has had a couple of nasty experiences (you can't be a die hard shopper and not). I haven't decided whether or not to disclose the identity of the person I'm talking about, because I don't believe in slander, but I feel like letting you know who might encourage the designer to change their ways. Or if not that, at the very least warn you against purchasing there. For now I shall give the gift of anonymity, and I hope my advice is helpful to folks out there :)