PLEASE for the love of all crepe...do not just camp around the store for no particular reason if you have absolutely no intention of buying anything. No I don't mean that people shouldn't browse the store, lol or just never come here, but there's not a whole heck of a lot to sightsee in the Twas store. ;)
Also please don't tp your friends in with you just so they can stand around with you and wait while you shop. You won't be gone that long, I'm quite certain they won't miss you while you are.
Yes this includes masters bringing their subs to the store with them. Sure I know, it's part of your RP. But there is an entire grid out there, besides you two, or three, or four, and some of us choose to go to the store get what we need and leave. We can't do that when the sim bogs way down though.

As laggy as these sims can be all on their own, it helps when we do our part to cut down on that, not increase it.
The delivery system is taxed enough as it is, when the sim slows to less than a snail's pace, there's a problem and that's NOT the time to go to the store, stand around in big groups of people and just stand there for an hour, or more. It wouldn't be nearly as bad if the sims weren't already taxed, but they are, so we must be mindful of our own footprint.

Please be kind to your fellow shoppers and don't "play" in the stores :(

(see Malevay, this is why having a store on sims like "Roo" and Twas, isn't really the best idea in the world. Maybe you really ought to revisit that marketplace idea now, eh?)