NEW YORK (CNNMoney.com) -- Small-business owners have discovered that they don't need a store to have success.

With more than $45 billion in yearly gross merchandise sales, eBay's virtual marketplace has spawned many lucrative businesses.

Financial analysts estimate that some 600,000 eBay sellers known as PowerSellers run either a full-time or significant part-time eBay business listing millions of items every day, according to Skip McGrath, author of "Titanium eBay: A Tactical Guide to Becoming a Millionaire PowerSeller."

eBay PowerSellers sell anywhere from $1,000 to more than $150,000 monthly on the site and also get a high level of positive feedback - with a 98 percent or better rating by other eBay users.

eBay "is a ready-made business platform," McGrath said, because of its low barrier of entry, high traffic and millions of customers with credit-card information on hand and ready to use.

Jonathon Garriss worked in a small shoe store before he started selling overstock on eBay; now he runs Gotham City Online, a $6 million to $8 million business selling shoes on eBay.

To get your hands on a piece of that $45 billion, McGrath offers these tips that could help you become a PowerSeller.

Learn to buy before you sell. By racking up experience buying, eBay-style, you will learn to bid successfully, how PayPal works, how to post feedback and how buyers and sellers communicate with each other.

One man's junk is another man's treasure. For starters, McGrath suggests finding something in your home that is usable but that you don't want anymore and sell it online. That way, you can establish yourself, get the hang of selling and use the proceeds from those first sales to buy more merchandise.

Sell what you love. If you love to fish, sell fishing equipment. After all, if you know something about the products you are selling, you'll be better at distinguishing between the good and the bad items out there, as well as pricing and writing descriptions. The more specialized your product niche, the better. Customers will begin to know you for your wares and come back to you again and again.

It's not only what you sell, but how you sell. Whether it's with free shipping, or a very high level of customer service, set yourself apart from the masses. Consider adding a picture of yourself or a personal touch to the description. After McGrath added an audio message to many of his listings, he noted a dramatic increase in sales. And be sure to pack and ship your items professionally and in a timely fashion. Including a handwritten card or note is a nice touch.

Hone your headlines. If you don't write good headlines, nobody is going to click on your auction and you're not going to sell anything. Seems pretty obvious right? But it's not quite so simple. When writing headlines, keep the user in mind; try multiple spellings (i.e., hairbrush, hair brush) and be as descriptive as you can (i.e., tortoise shell, made in London, England).

A picture is worth a thousand words. When you photograph your item, capture it in its best light. "Nobody wants to see dirty dishes in the background," said McGrath. Also, include close-ups and details (the underside, the label, the tag etc.).

Get into the description. Don't just list the item's features (size, color, shape, what it does) but also describe the benefits (why it's different, why you like it). Add sentences like "this is the best one of its kind, because..."

Think big. McGrath recommends running 100 or more auctions at the same time. That way, you'll not only get noticed by more people, you will sell more stuff and boost your monthly take, which can then boost your ranking within eBay's PowerSeller tiers.

Bronze sellers bring in average monthly sales of $1,000 a month, silver sellers log $3,000 in monthly sales, gold sellers bring down $10,000, platinum take home $25,000 and titanium sellers, the highest level, bring in $150,000 a month.

For the advanced seller, several auction-management companies - including Vendio, Channel Advisor, Auction Hawk and eBay's own Turbo Lister - can help manage inventory, transactions, post-sale processes and communications with customers.

Almost anyone has what it takes to make it to the upper tiers, although making it in the eBay world does require some diligence and patience. All sellers, at some point, might have trouble unloading a product or dealing with a difficult customer, but with these techniques the serious seller can step up their game.

Now that you have the tools of the trade, get your gavel and go.

A new twist to the 'mom and pop'