There are various ways you can do this.
The best way to do this is to post daily. To better streamline your ad I would copy and paste your description for speed and efficiency.
If you are not limited by location I would post on CL to the largest cities in the U.S. These listing have more views so in turn you get found and seen by more traffic.
I've been hustling on Craigslist, OfferUp and other local classifieds ads for years. Beginning years ago when I used to attend storage auctions to running entire businesses just selling locally through classifieds ads.
The best thing you can do is just put together quality listings, that part is fairly simple. Write a detailed post about what your selling. Remember to answer any potential questions a buyer may have. If your selling a piece of clothing describe the material, condition, how it's washed, the measurements. Include a number of quality photos from good angles and with good lighting. This will put you ahead of 90% of listings on these sites.
Outside of that try to use relevant keywords without keyword spamming as it annoys buyers and gets untargeted people looking at your listings. If you're describing a piece of clothing maybe list the brand, similar brands, and words like fashion, style, mom, teens, ie whomever the item would appeal to.
Another important thing is to post consistantly. Many people browse these classifieds sites often and after a couple days or even more so a week or more your listing is going to get lost in the results.
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