The rate of return is specific to a company and it is related how the company gets its funding for projects [1]. Moreover, it is the rate of return that the investor expects or the cost of borrowing money [1]. Other words, to determine R one would need to consider how much debt a company has or how much it owes, and how much money it gets from preferred and common stock a company invests in. Some factors that influence the R is one the rate of growth in a company’s revenue and earnings. The company’s growth rate can impact its stock price and thus the return the company gets from owning it.

A project should have a positive NPV because this will mean its returns exceeds what the financial market offers on investments of similar risks. Thus, companies have a concept called weighted average cost of capital (WACC) associated with a project, which is the minimum required return a company needs to earn to satisfy all of it investors, including stakeholders [2]. Thus, to come up with a project’s cost of capital, a company’s head must examine what the capital markets offer. Three major factors influence the rate of return: the cost of equity, the cost of debt and cost of preferred stock. Cost equity is the investment or funding a company get from equity investor. The cost of debt is how much a company owes to a lender. Lastly, the cost of preferred stock is a fix dividend expense a company has to pay for a certain period.

Reference:
[1] https://hbr.org/2014/11/a-refresher-on-net-present-value
[2] Ross, Stephen A., Randolph W. Westerfield, and Bradford D. Jordan. "Chapter 14 Cost of Capital." Fundamentals of Corporate Finance. 11th ed. Macquarie Park, NSW: McGraw-Hill Australia, 2003. N. page. Print.

The rate of return (R) is used as the discount rate for future cash flows to account for the time value of money. Companies may often have different ways of identifying the discount rate. Common methods for determining the discount rate include using the expected return of other investment choices with a similar level of risk, or the costs associated with borrowing money needed to finance the project.
If the NPV of a prospective project is positive, the project should be accepted and the investment would add value to the firm. However, if NPV is negative, the project should probably be rejected because the investment would subtract value from the firm and cash flows will also be negative. Factors that affect the rate of return:
Macroeconomic conditions- Economic slowdowns lead to low employment, which usually means lower profits and stock prices. The resulting weakness in the stock markets could improve bond prices as investors move funds to the relative safety of bonds. Rapid economic growth can lead to higher interest rates which would makes credit more expensive.
Risk factor-changing regulatory environment, competitive pressure. However, the required rate of return is higher when the risk is high and vice versa.
Regulations - deficits reduce government flexibility and may results in higher borrowing cost for businesses.
Political instability- increases risk for investors and businesses and lower their confident level because low visibility of rate of return. Investors would try to avoid countries who change government frequently.
http://www.investopedia.com/walkthrough/corporate-finance/4/npv irr/introduction.aspx#ixzz4e3XdfhjH

It is difficult to exactly pinpoint the required rate of return due to the various estimates and preferences that differ from one decision maker to another.The various factors that determine the rate of return are the risk return preferences, inflation and the capital structure of the firm. Each of these factors greatly affect the intrinsic value of the asset. It requires lot of experience and practice to determine the perfect rate of return,that makes the investment decisions more predictable in the future. The bottom line is to refine your preferences and estimates for any investment to get a good rate of return.

Simply, the rate of return is profit, it could be a dollar amount or percentage of how much was invested. It is impossible to know exactly what the rate of return is just as it is impossible to predict the future; the best that can be done is to make an educated guess. Factors that can influence this guess and subsequently the rate of return are: time value of money, whether or not the rate is reinvested (compounding), if the rate of return is through foreign currency, and whether or not the investment venture is risky. Time value of money can be estimated with longitudinal studies; possible inflation rates, bank's interest rates? Deciding to reinvest the rate of return would mean more profit; return is higher for compounded interest than simple interest. For foreign currency your are estimating the exchange rate. Investing in a risky stock might produce a high rate of return if it does well or a heavy loss if it does poorly. The best rate of return might come from the following: investing in a low risky stock that pays out quarterly but then reinvesting that return next quarter.

The rate of return is similar to Return on investment (ROI) in the sense that there exists an amount or percentage of money coming back to the investor(s). Factors that influence the rate of return include the current climate in the market, inflation rates, bank's interest rates (as Agnieszka stated above), the speculation around which can shift stocks of various companies sometimes instantaneously. The rate of return needs to be calculated/estimated while being cognizant of the above factors. Purchasing risky stocks can hinder or increase the rate of return. Many times, however, it is hindered. Stocks can be invested in either as a long term or short term investment. The rate of return can be more steadly or higher as a long term investor as opposed to a short term day trader.

In short, it depends.

To answer the first question, we need to look at the factors that influence R. Aside from what the others have said, there is also the companies financial situation and overall business goal. If it is a startup with lots of debt then the R value will be much higher since time is critical factor that will determine if the company stays afloat but if this is simply another launched product that is expected to have stable sales within the foreseeable future then R may be very small. In fact R may actually be calculated using the equation above with projected gains of the product if you are only concerned with getting your money back in lets say 1 to 5 years.
One problem with this is that unless this is used retrospectively or with some historical data at least(in many cases its not), all the components are dynamic changing the factors that affect it completely(which is usually the case and why R is studied so extensively). If the total initial investment needed is not known or changes throughout the project due to murphy or scope creep then all the previous projection change since the time need to get your initial investment will increase if the initial R remains constant. Defining what the goal of the project is, in more concrete or realistic terms than maximize profit, will help set the scale for determining R. The factors that can affect R can be time for ROI, market(gain per unit time), resources available(investment), cost incurred per unit time(used to set a threshold for minimum income per unit time to stay within the goal), overall business model(expansion vs. optimizing and maximizing profit), risk, and business condition/future plans.