Online Auction Sites:

Ebay is likely the most well known option for selling sports cards online through auctions. There is immense traffic on eBay with millions of active buyers bidding on cards every day. As the world’s largest online auction site, you can list individual cards, sets, or your entire collection and let the market determine the price. eBay takes a final value fee that is typically 10% of the sale price. Some benefits are immense buyer reach and ability to set reserve prices. Downsides include fees and risk of issues with shipping or payments.

Another popular auction site is Heritage Auctions. They specialize more in high-end, valuable cards but also accept normal cards. Expect lower overall traffic but possibly higher prices with established professional seller to assist. Advantages are specialist site focused on collectibles and authentication of truly valuable cards. Disadvantages are higher listing fees and smaller buyer base.

Sports Card and Memorabilia Sites:

Two of the most well-established sports card sites perfect for direct sales not auctions are Blowoutcards.com and Sportscardforum.com. Both have large active communities and allow you to list individual cards or lots for a fixed price. Benefits are no listing/selling fees, targeted sports card collector audience, and ability to include photos and details. Downsides are lower overall traffic versus auction sites. You have to set competitive fixed prices.

Local Card Shops:

Taking your cards into local independent card shops allows you to potentially sell to other collectors in person. Upsides are immediate cash payment and assessment of condition. Most shops will just buy collections outright with an offer after assessing condition and value. Disadvantages are shops need profit margin so you won’t get true market value, limited buyer reach, and shops may not want common cards.

Online Consignment Stores:

Services like consignment stores allow you sell your cards through their online storefronts for a commission, typically 20-30% of sale price. Major ones are DaCardWorld, SportsCardSellers.com, and PWCC Marketplace. Advantages are ability to tap their expertise, reach of established online store, and cards get prominent visibility. Drawbacks are the large commission percentage charged and cards may take time to sell through their inventory.

In-Person Shows and Events:

Attending major national or regional card shows gives access to thousands of collectors gathered in once place on a given weekend. You can rent a table and bring your cards to sell yourself or simply walk the aisles and try to make deals with other dealers. Upside is instant offers and interaction but you have to invest in travel and table space. Tougher to reach scale with one-off weekend shows.

Facebook Groups and forums:

Active Facebook groups dedicated to trading/selling specific sport franchises are a decent alternative way to move cards locally or nationally. Make a post with details and photos, and let potential buyers reach out to ask questions and negotiate a sale. Free exposure but smaller targeted audience versus mainstream sites. Can be hassle arranging payments and shipping with unknown online buyers.

When choosing where to sell, consider factors like your collection size, target price points, desired time effort, and whether you aim for single high-value cards or want full buy offers on entire lots. With diligence, research, and playing to the strengths of each platforms, you can maximize profits reselling your sports cards collection. Just be sure to only do business with trusted established sellers or platforms to avoid scams.