I used one a number of years ago (also from Radio Shack, in fact) and it seemed to work fairly well. In our current house, however, weak signal problems led to a number of service calls from Time Warner because the cable modem couldn't keep a connection and the digital cable boxes were having trouble as well. The cable company ended up providing their own booster for me. Thirty bucks may well be worth it to save the hassle of dealing with a service call from your cable company, but if it doesn't get you where you need to be you might consider that recourse. Unless the signal needs boosting because you've split the signal yourself a bunch of times, you can make a pretty reasonable case for them to get your signal strength up to where it belongs.