Unlike some of the other sites, with Inbox Dollar, you essentially sign up to take advantage of whatever Inbox Dollar makes from their advertisers. They will send you emails which they get paid per receipt of you reading them or clicking a link. In turn, they give you a cut. Not to ruin your day but it's a rather small cut. The links that end up paying out the most usually have some stipulations attached – such as signing up for a service. This can end up being a lot more hassle than its worth and we recommend you pay VERY close attention to the stipulations.
The only problem with rewarding consumers for taking online surveys is that it gives them the incentive to cheat. The more surveys you fill out, the more points you get. So people get creative: They randomly answer survey questions as quickly as possible, establish multiple e-mail addresses to answer the same survey five or six times, or lie about their demographic (a white male says he's a black female, for example) to participate in surveys for which they otherwise wouldn't qualify [source: Frost & Sullivan].