(FORTUNE Magazine) – Cable television is generating a new kind of excitement, but not over Hollywood stars or blockbuster specials. The attraction is shop-at-home television: merchandise sold at discount prices on networks that show nothing but commercials. The idea was pioneered by the Home Shopping Network of Clearwater, Florida, and Wall Street loves it. Last July, HSN began national cablecasts of its 24-hour network, in which pitchmen hawk goods from garden tools to crystal bowls. Just call the toll-free number on the screen and charge the purchase to your credit card. % In its first eight months of national operation, HSN had sales of $63.9 million and profits of $6.8 million. The company went public in May at $18 a share. Its stock traded immediately at $42 and has since steadied in the mid- 70s. Success breeds imitators. This spring, the COMB Co. -- a Minnesota-based company controlled by financier Irwin Jacobs -- launched a similar enterprise, dubbed the Cable Value Network, with Tele-Communications Inc. of Denver, the largest U.S. cable system operator. Since then, COMB stock has jumped from $20.125 a share to $63.875. Now Warner Communications and United Cable Television Corp. have announced plans to buy a stake in the network. Financial News Network and Horn & Hardart, among others, have suggested that they might start their own shop-by-TV operations. While Wall Street is infatuated for the moment, some security analysts are skeptical about the long-range prospects for TV shopping. Says Jeffrey Russell, who follows broadcasting for Drexel Burnham Lambert: ''Do we need six shopping networks? Not likely. HSN and COMB have high-profile, well- financed backers, but I'm not sure there's room for all the others.''