VANCOUVER — Victoria-based Terapeak and sister company Advanced Economic Research Systems Inc. began in 2002 to provide sellers on eBay with the tools to research products and markets.

So it makes sense, now that eBay is retiring its own service, eBay Marketplace Research, that Terapeak will be there to fill the void.

Terapeak, which earns its revenues through monthly and annual subscription rates paid by eBay sellers, will be offered to all existing eBay Marketplace Research subscribers when eBay retires its own service on Sept. 15.

The Victoria company, started by brothers Andrew and Anthony Sukow in 2002, has two sides.

AERS provides bulk data to large companies that need business-to-business data.

Terapeak, a subsidiary of AERS, is a business-to-consumer enterprise designed for eBay users, mostly sellers but also buyers who want to research products and prices.

"If somebody is selling on eBay, whether they're a first-timer or a big company, they use Terapeak to do their research," said Denise Hogue, Terapeak product manager.

"Instead of doing trial sales or putting stuff on the market not knowing what it's worth, they can use our software and find out what things are worth on eBay, what the sell-through rate is, how many are selling."

The software shows all the closed transactions on eBay for the last 90 days, as well as "trending data" that go back over a two-year period.

"For the person sitting at home building their business out of their spare room, this allows them to look at the marketplace on eBay before they invest in their business," says Hogue.

Buyers can also use it to evaluate items.

Jim and Barbara Nelson, whose Grandpa's Trading Company sells items on eBay, say Terapeak is invaluable to them.

"Terapeak provides you with data on the best time to begin your listing, best day of the week and time of day," Jim Nelson said in an email.

"It shows you market trends and analysis that you can customize to your specific niche. You also have the the capability to search for the merchandise your competition sells by doing specific seller searches and looking at their sold items and listings."

The subscription fee is $24.95 US per month, with a special annual fee of $120 for North American data.

The fees are slightly higher for international data.

AERS also relicenses its data to other companies that want to produce a market research tool.

Laura Della Torre, market data manager for eBay, said eBay's decision to retire eBay Marketplace Research gives Terapeak a good opportunity.

"We want to support our partner companies like Terapeak, and since research is Terapeak's specialty, they have the ability to focus on their core competency and give eBay users an outstanding product," said Della Torre in an e-mail exchange.

In addition to Terapeak, eBay sellers and buyers can also go to Vendio and HammerTap for their research needs.