COMC is website for buying and selling collectibles. Unlike competitors such as eBay, Beckett Marketplace, and Sportlots, the company stores each seller's items and sends out his orders.
COMC has several million trading cards for sale, all located at the company's headquarters in Redmond, Washington. Each card on the site includes a front and back scan, and details like set year, set name, player name, card number, print run, and serial number.
There are over 10,000 sellers on the site, and you have the option of buying items from different sellers and having them all shipped together.
You can make purchases using two different methods. One is to add them to your cart and check out. The other is to buy Store Credit, use it to buy items, and then request a shipment whenever you're ready. The second options enables you to make your purchases at different times and then have them all shipped together. It also allows you to make offers to sellers, instead of paying their full asking prices. (To make offers, click the Make Offer button next to a card's price, or add items to your cart, and then click the Make Offer link at the top right of each page. Keep in mind that different sellers have different set policies regarding offers. They can set their minimum offer anywhere between 50% and 99% of their asking price, or they can disable offers altogether.)
The prices of cards on the site vary greatly--but typically, if a card has a high print and there are quite a few copies available on the site, you can expect to pay relatively low prices, while rare and/or high end cards tend to have high asking prices. It's very uncommon to find a reasonably priced 2000 Bowman Chrome Tom Brady rookie or LeBron James auto on the site, but you can find a plethora of other items at eBay or below eBay prices.
Sellers send their cards to the company's headquarters, and pay a processing fee of about 35 cents per card. After the cards are processed, sellers price them--and as soon as a sale is made, a 5% fee is taken by the site, and the remainder of the proceeds goes into a seller's account in the form of Store Credit. Sellers can cash out their Store Credit by paying a 10% fee, or use it to buy other items on the site. You can also use store Credit to pay the processing fees for a future shipment of cards, or redeem it (minus a fee) for Blowout Cards gift certificates.
If you enable offers, the site will notify you any time a buyer makes an offer on one of your items. The site makes it quick and easy to accept, reject, or counter any offers you receive--and also it lets you set minimum offer levels.
In my opinion, the site is best for selling lowing print run cards of all types. It's also good for higher print run cards that are in extremely high demand.
Having an account with store credit allows you to relist items that you buy on the site. For instance, you can use your store Credit to buy a card for $10, and then immediately relist it on the site for $20. The $10 purchase price will be deducted from your Store Credit, ownership of the card will transfer to your account--and should the card sell for $20, the money will be added to your Store Credit (minus the 5% fee on all sales).
Items listed at over $0.75 are charged a $0.01 a month storage fee (the first month is free for items you send into the site). High volume sellers can opt to pay $50 a month and increase the limit from $0.75 to $2.50 (--which will result in some sort of savings if you have over 5,000 items priced between $0.76 and $2.50).
Account holders can access a wide variety of functions and information through the My Dashboard section of the site (which is accessible by clicking a My Dashboard link in the top right corner of most pages [after you've logged in]). COMC keeps track of all of your buys and sells, and allows you to easily price and reprice items, make and respond to offers, request a shipment of cards, cash out your store credit, and do a whole lot more.
As a seller, I prefer COMC to its competitors. The fees are a little high--but get more than you pay for. The site does have its flaws, but all in all, it's pretty amazing, and makes it easy to price items and track your account's activity.
My main complaints are that you can't run complex searches for cards, change your email options, sort items according to their popularity or Suggested Wholesale Price, or easily switch from browsing through a base set or insert set to browsing through the master set. Also, search results tend to be a bit cluttered and clogged up at times, because for each card on the site, there is a separate listing for every graded version and every condition bucket. For instance, if you search for 1989 Upper Deck cards, you will literally come across dozens of different results just for the Ken Griffey, Jr. card--PSA 9, BGS 9, Raw, Mint, and the list goes on and on. It would be much easier to have all the 1989 Upper Deck Ken Griffey, Jr. results consolidated into one result--you click on it, and then you can see the dozens of different varieties on 1989 Upper Deck Ken Griffey, Jr. cards.