Amber Kealey was struck by my musings last week about a Philadelphia start-up that has developed a system that transfers cash via a text on a cell phone.

I had written that as simple as it seems to text money, I'd be more likely to pay with the cash in my pocket than use the system that Venmo Inc. has built.

And that's what prompted Kealey to e-mail. She's been using Venmo for several weeks and has found it valuable for one big reason: The public-relations professional never carries cash.

Before discovering Venmo, she'd use her debit card or a credit card for a night out with friends at a restaurant. Now, she might still use plastic, but when it comes time to split the check, she and her friends can text one another to settle accounts on who owes what immediately.

Plus, unlike me - who often wonders where all my cash went - Kealey says e-mail updates she gets from Venmo outline exactly who got her nickels and dimes.

Still, carrying no cash creates minor problems for Kealey, such as when it's time to tip a hair stylist or manicurist. Many salons frown on putting tips on credit cards.

Will they accept a tip by text? She's hoping to convince them to try.

And from what I heard in Venmo's elevator pitch, that's exactly the kind of envelope the small company is hoping its users will push.

IPO for Zipcar?

Zipcar Inc., one of two car-sharing services operating in the area, hopes to raise $75 million in an initial public offering.

Zipcar, which is based in Cambridge, Mass., has been doing business in Philadelphia since 2007, when it bought Flexcar Inc. Its prime competition here is the nonprofit PhillyCarShare, which saw more than 14,000 residential members make at least one reservation during 2009, according to a recent economic-impact study.

But just because the bigger Zipcar is for-profit doesn't mean that it has profits. According to a registration statement filed with the Securities and Exchange Commission, Zipcar had a net loss of $4.6 million on revenues of $131 million in 2009. That net loss was down from $14.5 million in 2008.

Car-sharing is a growing market. Zipcar cited a Frost & Sullivan study that estimated car-sharing revenue in North America will rise to $3.3 billion in 2016 from $253 million in 2009.

Fair and balanced

The SEC will hold a public hearing in Washington, D.C., Wednesday on whether the structure of U.S. equity markets is fair, transparent and efficient.

The one local financial expert on the agenda is Gus Sauter, chief investment officer of Malvern-based Vanguard Group Inc.

He'll be on a panel discussing "market structure performance and price volatility." Other panels will examine the role of "dark pools," those private trading systems that don't reveal their quotes to the public, and high-frequency trading, which uses fast computers and complex algorithms to buy and sell securities.

Vanguard was one of dozens of firms and individuals to have submitted public comments to the SEC. In a letter dated April 21, Sauter wrote that the mutual-fund firm has benefited from the competition among the more than 40 trading venues, and the resulting reduced transaction costs.

Don't expect Vanguard to be leading the charge against dark pools and high-frequency trading. "We believe much of the public concern over 'high frequency trading' is misplaced and believe such activity, appropriately examined, contributes to a more efficient market that benefits all investors," Sauter wrote.