Hydroseeding has become a widely used alternative to the more traditional method of sowing dry seeds and then laying down mulch as a separate top layer. There are two major benefits to hydroseeding: rapid sprouting and growth of seeds, and the prevention of soil erosion. One of the most common applications of hydroseeding is the reclamation of burned land, such as in the aftermath of a wildfire. In that case, the hydroseeding process may simply lay down a layer of soil stabilizer in order to curb erosion and prevent the introduction of non-indigenous varieties of plant life from taking hold. 
The sprouting and early growth of seeds, or germination, is sped up in hydroseeding due to the high moisture level retained by the mulch in the slurry mixture. Depending on the application, fertilizers can be introduced to the slurry to further promote crop health and to encourage quick growth. The process of hydroseeding has all but replaced traditional methods in the seeding of large commercial locations, such as highways, golf courses, and new housing developments where the native landscape has been mostly razed. As hydroseeding is a one-step process, the manpower expense is considerably less than the traditional dry seeding, mulch, and water approach, or even the laying of sod or turf. 
For homeowners, the benefits of hydroseeding are manifold. The results are quick; depending on climate, grass can appear on a barren lawn inside of a week of hydroseeding. The slurry mixture used for residential hydroseeding is green, which looks much more attractive than the traditional straw mulch used to protect a dry seeding. Straw also contains a high weed seed content; the hydroseeding slurry does not. In addition, straw mulch leaches nitrogen from the soil during decomposition, which can compromise future lawn health. 
The laying of sod has traditionally been the method of choice for tract housing developers, but has been largely replaced by hydroseeding in recent years. Sod is expensive, and it doesn't always take. It's not uncommon to see sod that's been down for a year or more to appear as if it could be rolled up like a carpet and carted away intact. In contrast, this risk is practically non-existent with hydroseeding.