1. ConvenientInspiration and motivation are fragile states of mind that can easily be lost by having to spend time setting up your regular rig. So if you do not want to lose a potential hit song or you want to keep your practice right on schedule, a small practice amp lets you conveniently and quickly plug-in and play. Newer practice amps even come with a myriad of modeled amps and effects that you can easily access, keeping your practice interesting without having to waste much of your precious time on tweaking. Even big name artists who use truckloads of gear when recording and performing confess that they can get acceptable tones out of their practice amps with minimal setup.
2. PortableBecause practice amps are compact, they are easy to carry around, allowing you to play the guitar "wherever" you are motivated or inspired to play. Professionals and big name guitar players know this all too well, many of them have a backstage practice amp for warm up routines before performing, while others have their practice amps on their tour bus, to play with new musical ideas for their next hit song while on tour. For musicians who love the great outdoors, there are modern practice amps that can be taken anywhere that are powered by batteries. Portability is an important need that practice amps are excellent at satisfying.
3. QuietSince not all of us have acoustic treated rooms for playing with loud amps, the lower volume levels provided by practice amps become a practical advantage. This is especially important when you live in an apartment and you don't want to be on bad terms with your landlord or neighbors. Although it won't have the "feel" of a powerful amp moving the air, practice amps provide acceptable tone that you can use to improve your skills or to simply have fun, all without making your family or neighbors mad. In situations where you share a room with someone or if inspiration strikes late at night, many of the practice amps today will let you plug-in your headphones for quiet practice time.
4. EfficientThe compact design of practice amps make them inherently efficient, but manufacturers have taken it to the next level by adding even more practice friendly features. Most, if not all, practice amps will let you plugin your music player via an aux in port so you can play along with your favorite tracks. Modern amps even come with built-in backing tracks, allowing you to jam with a virtual band that cover a variety of musical styles. Although nothing beats playing with a real band, jamming with a track greatly improves the efficiency of your practice time. It helps improve your sense of time, feel and groove - all without having to worry about your band members not showing up for practice. Some practice amps even come with a built-in metronome which is a critical element of practice that some players tend to ignore.
5. ConnectedThe popularity of practice amps resulted in tight competition among manufacturers, this competition results in ever increasing features that at the end of the day will benefit us players. One notable feature found on modern practice amps is USB connectivity, which turns your amp into a fully functional audio interface. With this feature, you can conveniently capture your guitar playing directly to your computer - increasing the value that you are getting for your money. You can use it to record, or to apply a number of software based effects to your signal right on your computer. Aside from audio interfacing capability, some amps let you tweak the settings through your computer, and they allow you to "update" the amp via firmware upgrades.
6. AffordableThis is easily the main reason why practice amps are selling like crazy. For less than $150 you can get yourself some of the best practice amps on the market with impressive features. With so many great practice amps available, there is simply no excuse for not owning one. The only downside is that the amplifier market is currently saturated with a large pool of practice amps, which can be confusing for beginners who are looking to pick one that's right for them. To help with this, check out a practice amp roundup to narrow down the list of possibilities to a select few, like this one from GuitarSite.