A sputtering economy, implosions at financial institutions, or just plain bad management -- on any given day, investors can name a number of reasons to sell a stock. Yet while panic is never beneficial to investors, it's good practice to play devil's advocate with investments from time to time.

In Motley Fool CAPS, more than 120,000 members have weighed in on nearly 5,400 stocks, sharing bullish and bearish opinions alike. A total of 3,738 such members have weighed in on online auction maven eBay's (NASDAQ:EBAY) chances of success. I've already plucked out some of the bullish rationale backing eBay today, so here are three counterpoints to consider, courtesy of CAPS:

1. Slowing growth
While its Latin counterpart MercadoLibre (NASDAQ:MELI) is bringing in strong profits, eBay paints a bleaker picture. The company expects of a weak fourth quarter, with earnings that lag both analyst expectations and their year-ago counterparts. Tracking firm comScore predicts flat online holiday sales this year, as sites like eBay, Amazon.com (NASDAQ:AMZN), and Overstock.com (NASDAQ:OSTK) face heavy competition from deep discounts at retailers like Best Buy (NYSE:BBY) and Wal-Mart (NYSE:WMT).

2. Unhappy customers
Many longtime eBay buyers and sellers are unhappy with the new pricing eBay has added to its auction site. Selling prices have risen, squeezing many sellers out. Some investors feel that may doom a business critically dependent on both buyers and sellers.

3. Ineffective change
Just as many investors doubt that Yahoo!'s (NASDAQ:YHOO) leadership shuffle can turn the struggling search engine around, eBay's investors aren't much happier with all the structural changes that were supposed to improve the company. eBay's traffic levels are still deteriorating, and many shareholders have lost faith both in its auction site and its shares.

eBay has survived and thrived despite dozens of prior obstacles. Can it regain its luster? Wherever you stand on the issue, CAPS makes a great resource to augment your own analysis.

To see what the very best CAPS members are saying now about eBay, just click on over to Motley Fool CAPS and have a look -- it's all free, and your opinion is always welcome.

Place a bid on further Foolishness:

The Motley Fool Stock Advisor service looks for companies with strong management poised to beat the market over the long haul. To see all the stocks that have helped Tom and David Gardner beat the market by 27 points on average, take a free 30-day trial.

Fool contributor Dave Mock takes naps to pass time and rejuvenate lost brain cells. He owns no shares of companies mentioned here. Wal-Mart, eBay, and Best Buy are Inside Value selections. eBay, Best Buy, and Amazon.com are Stock Advisor selections. The Fool owns shares of Best Buy. The Fool's disclosure policy has recurring nightmares of Blinky, Pinky, Inky, and Clyde chasing it through an endless maze.