Based on Los Angeles’ 100 fastest-growing public companies, there’s a full-on sales boom going on.

Led by high-tech issues, 20 of the 100 reported greater than 100-percent increases in sales in their latest fiscal year, compared with the prior year.

Of the 10 fastest-growing companies, seven are in high-tech industries, with Los Angeles-based SmarTalk TeleServices Inc., a provider of calling cards, leading the way. Its revenues soared by more than 3,200 percent.

Also posting a gigantic revenue surge up 21-fold was No. 2-ranked Peerless Systems Corp. of El Segundo, which went public last year, and which makes software for imaging systems, such as printers, copiers, fax machines, scanners and emerging color copy products.

Indeed, 27 of the top 50 companies are technology based, an indication of the importance of high-tech to the stock market, and to the local economy.

“That’s what is not recognized by the media or by investment bankers or by venture capitalists, just how many high-tech companies are here in Los Angeles,” said Joel Kotkin, Pepperdine University lecturer and local commentator.

Also prominent on the List is the entertainment industry, with 19 companies in film, radio, television, music or entertainment software.

The entertainment catagory is remarkably varied, ranging from No. 4-ranked Legacy Software Inc. of Los Angeles, a maker of CD-ROM entertainment/educational software, to the Burbank-based behemoth Walt Disney Co. (No. 43). Burbank-based TV programmer Dick Clark Productions Inc. has been doing well, with revenues surging by 58.3 percent enough to earn a No. 39 ranking.

But it is not only hot, cutting-edge growth companies or entertainment stocks that make up the List.

There are restaurant chains (Calabasas Hills-based Cheescake Factory Inc., ranked No. 65), insurers (Los Angeles-based SunAmerica Inc., No. 61), real estate investment trusts and even a manufacturer of premium golf clubs (No. 25-ranked Coastcast Corp. of Rancho Domingeuz).

There are cosmetic distributors, health care companies and a chain of veterinary hospitals (Santa Monica-based Veterinary Centers of America Inc., ranked No. 31).

Despite the continued exodus of high-profile public companies Northrop being the most recent example the List shows a remarkable breadth of strength in revenues, with the 50th-ranked company, Beverly Hills-based securities firm JB Oxford Holdings Inc., posting more than a 45 percent gain.

Even the 100th company, Guitar Center Inc., an Agoura Hills retailer of musical instruments, posted a 25 percent revenue jump.

What is at the heart of this surge in revenues?

One reason is that the state and U.S. economies are expanding, providing a fertile environment for companies.

Another factor is that American companies in part due to the good economy and competitive pressures have been investing in plant, equipment and computers. That demand has boosted the fortunes of companies that supply such capital goods.

So businesses like No. 3-ranked NetVantage Inc., the El Segundo-based providor of switching devices for local networks of computers, are well-positioned to grow.

Also, the nature of exchange-listed companies has changed in the last 20 years, with managements and boards placing greater emphasis on revenues and profits. Very often, management is incentivized by stock options.

The results are seen in the long-run bull market, and also in aggressive, small-growth companies going hard after sales.

“I don’t know if management incentives are anything new, but they are much more pervasive than in the past. I think (revenue) growth reflects the entrepreneurial spirit of local companies, and the management incentives,” said Harry DeAngelo, a business professor at USC.

Others credit the mergers and acquisitions boom, which is leading public companies to acquire or be acquired.

“For many of these medium-sized public companies, it is either buy or be bought,” said Scott Adelson, managing director at Houlihan Lokey Howard & Zukin, the Century City-based investment bank and financial advisory firm.

“Besides, if you are under pressure to increase revenues and earnings, it can be easier to achieve that by acquisition than through internal growth,” he said.

One of the fastest-growing public companies No. 5-ranked Craig Corp. exists for no other reason than to make acquisitions, and manage controlling interests in other companies.

In addition, noted Adelson, Los Angeles tends to be a middle-market region, where big percentage jumps in revenues are more likely than in areas where Fortune 500 companies dominate.

“That’s just the nature of business. It’s a lot easier to go to $30 million in sales from $20 million, in a growth industry, than to go to $6 billion from $4 billion,” he said. “Big percentage increases just get harder when the dollars get larger, in absolute terms.”

Another factor contributing to revenue increases is that public companies often have better access to capital than private companies. And that capital can fuel growth.

The mere act of going public can often raise expansion capital as was seen at No. 64-ranked Bonded Motors Inc., the South Central L.A.-based automobile engine remanufacturer which went public in 1996. “Before we went public, we couldn’t get a bank to talk serious to us,” said Paul Sullivan, treasurer at Bonded Motors. “After we went public and raised capital, then banks were willing to lend.”

Armed with cash, Bonded Motors has grown its markets and made acquisitions in the highly fragmented engine remanufacturing business.

The huge multiples on Wall Street are compelling many growth companies into the public arena, which in former eras might have stayed private. Going public can bring huge windfalls to company founders.