Sniping services operate under eBay's radar, but are vulnerable to changes the online auction site makes to is technology and software. Last week, some snipers were disappointed when one of the major vendors of sniping services had to deal with technical issues it said was caused by eBay changes.

Sniping is a cultural phenomenon unique to eBay buyers, where bids are placed in the last seconds of an auction to ensure winning the item while avoiding bidding wars. Sniping services offer users the technology to place last-minute bids automatically, rather than manually placing their bids at the last minute.

Last Friday, eSnipe's message board apologized to users for recent problems that caused some users to miss out on items due to missed bids. Tom Campbell, CEO of eSnipe Inc., told AuctionBytes that the problems were due to changes eBay made to its site. "The log in process (at eBay) was changed," he said, and his technical team had to fix eSnipe to deal with the change.

Chuck Eglinton of BidRobot, another sniping service, said his service was unaffected. "Because bidding services don't use an eBay API, eBay changes can affect one bidding service but not another." He added, "At BidRobot.com, programmers are alerted by 24 hour SMS messaging if more than five consecutive bids fail for technical reasons."

The API is eBay's program for developers so they can interface with the eBay platform under eBay's control, but eBay has not officially allowed sniping in the past. Developers at sniping services cannot utilize eBay's API program and must therefore "scrape" eBay data to place bids for customers.

"Frequently, users don't realize that eBay is a dynamic site," said Taylor from Bidnapper. "They are always making changes, some effect the bidding process or other services we provide." He said Bidnapper was not affected by the recent changes reported by eSnipe. "Although we believe changes have become more frequent, we don't have any statistics to back this up. We think eBay seems to make most of their changes during the summer months when their traffic is lower."

Bidnapper's Taylor said, "We have noticed that eBay changes effect all the sniper services differently. One change can completely break a service, while another could go through changes working just fine."

Dan Hite of Auction Sentry said there are some periods where he can go up to 3 or 4 months without having to fix anything, but once every month or two is about the norm. "eBay is always playing with their site it seems. Last November was the worst when they made some serious changes to how the sign in procedure was handled. Several software products were down for quite a while."

BidSlammer's owner said he had not noticed any changes since the "major" changes last December that affected everyone.

Some of the sniping services feel like they are on borrowed time. They believe eBay could make a technology change that could effectively block their services from the eBay platform, putting them out of business, or come out with a sniping service of their own. Possibly due to the controversial nature of sniping (eBayers seem to either love it or hate it), eBay has taken a hands-off approach so far.

As for sniping services, vendors must stay on top of eBay changes without any communication from the company.

According to Taylor, "It comes down to programming effectiveness, anticipating eBay, and luck."