You may also want to use a third-party website for advertising purposes: with well-placed ads on blogs and websites that match your target audience, you reach many potential customers. In this context, it also makes sense to check website traffic beforehand, since the more people that visit your site means that more people come into contact with your ads.
Web analytics is the measurement of the behavior of visitors to a website. In a commercial context, it especially refers to the measurement of which aspects of the website work towards the business objectives of Internet marketing initiatives; for example, which landing pages encourage people to make a purchase. Notable vendors of web analytics software and services include Google Analytics, IBM Digital Analytics (formerly Coremetrics) and Adobe Omniture.