Phone service upstart Vonage Holdings has filed initial paperwork with the SEC, the first step toward a possible IPO that aims to raise up to $250 million. Given the recent appetite investors have had for well-known consumer-related initial public offerings (Chipotle, Under Armour, to name a couple), the timing of this filing makes sense from the corporate perspective.

So, does the stock make for a good investment? Should the IPO come to fruition, we'll likely see a huge first day spike, allowing all of the investment banks' best clients to make a bundle. However, a closer look at Vonage's financials shows that any after-market valuation might be too high. For the first nine months of 2005, Vonage lost $190 million on sales of $174 million. Marketing costs totaled $176 million, a staggering figure.

IPO proceeds would undoubtedly go toward more marketing. While Vonage does have 1.4 million customers, how much are they actually worth? The Vonage service is a commodity, offering no differentiation from Comcast's service or anyone elses. Vonage is under cutting the competition on price ($24.95 for unlimited long distance calling to the U.S., Canada, and Puerto Rico) but there is no reason to think larger players won't attack that advantage in the future, and company's like Skype are focusing on free consumer voice services.

Much like other data and voice services, more competitors will enter the market, pushing prices down. Without a differentiated product offering, Vonage shares will likely be overpriced by retail investors should the IPO go smoothly.