. >> reporter: shawna barrons is a stay-at-home mom making a killing on used clothing. >> last month had $18,000 in sales. >> $18,000 in sales. >> yeah. >> how big is your closet? >> she finds cute items at consignment store, garage sales and posted them to an app called posh mark. >> it's so easy. if the price is right, i've sold stuff in 20 minutes. apps offer a thoroughly social way to buy and sell. followers comment on your shoes, your dresses. they even attend virtual purse parties. >> you know the worth of your item. you can convey to to your customers and say this is what i wear it with. >> reporter: and she didn't alone on tradesy this woman made $150,000 last year, this woman $117,000. on thread flip, this woman made $56,000. the online consignment industry is growing fast. users upload over $2 million worth of items every day from their owns this. that works out to an entire department store of clothing being listed and sold in one week in one-and. tip one, you have to be social. >> text back and forth and it just makes sales a lot easier. >> reporter: next she shays she's