Some of you believe that I'm guilty of allowing personal feelings to color my view of Palm (NASDAQ:PALM). You think I'm engaging in propaganda. You want numbers to back up my assertion that Palm is a likely underperformer.

Fair enough. Here are three numbers-informed reasons why I would sell Palm right now.

1. Momentum rarely lasts
As my Foolish colleague Nick Kapur pointed out, shares of Palm are up 900% since December. Yet in that time, little has changed with the underlying business. All we've seen is a preview of the Pre smartphone, which promises to challenge Apple's (NASDAQ:AAPL) iPhone and Research In Motion's (NASDAQ:RIMM) BlackBerry. The implication: Investors are betting that the Pre will be Palm's savior.

2. Premiums must be earned
What happens if this electronic messiah doesn't delight users? What if they like Sprint Nextel's (NYSE:S) network even less than iPhone users like AT&T's (NYSE:T) network?

Technologically, the Pre certainly looks like a winner, but investors have bid up shares of Palm so much that there's little room for the device to exceed expectations. Numbers bear this out. Since 2004, Palm has most often traded for an enterprise value-to-revenue multiple of less than 1. Today, the stock trades for more than twice that.

3. Protection is paramount
Palm's best attribute is its partners -- Elevation Partners, specifically. Having poured hundreds of millions into the business already, Bono, Roger McNamee, and the rest of their investing bandmates have little choice but to supply whatever capital is required to mend this business.

Indeed, Palm could need more greenbacks. The company last produced a full year of positive free cash flow in 2007, and its debt represented 127% of total capital as of February, according to Capital IQ. Should management seek further cash injections, they'll come by way of stock sales, further diluting the interests of existing investors.

Palm's issue isn't the quality, price, or configuration of the Pre. Yes, the early evidence isn't encouraging, but hey, it's early evidence. I'm more concerned that Palm is priced as if the Pre is already an iPhone killer -- and I'm not about to take those odds.

That's why I rated Palm "underperform" in CAPS this morning. I'm betting that the stock will lose to the market over the next six months. Think I'm wrong? Make your bull case using the comments box below.

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Fool contributor Tim Beyers had stock and positions in Apple at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. The Motley Fool is also on Twitter as @TheMotleyFool. The Fool's disclosure policy is a disclosure messiah.