No. You can sign up for free on all of them and start doing tasks to earn money right after that. Also, some websites give you a bonus cash just for becoming a new member.
You must be at least 18 years old.
No. You should never do that. If another account sign up on the website using the same IP address and device, both accounts will be banned and lose all their earnings.
No. You should never do that, otherwise you will be banned and lose all your earnings.
Each survey has a specific target and your profile will make sure that the right surveys will be sent to you. Also, some websites give you a bonus cash if you complete it.
When you start a survey you are sent to another website and when you complete the survey you come back to the source website again. The cookies are really important to keep the comunication between the websites and to allow you to receive your credits from the survey.
The number of surveys that will be available for you depends on the country you are from, the companies that make and sell products there and your personal profile. In other words, some people can have more opportunities than others.
Also, you should look for surveys on different days and time. Based on my own experience, weekdays are better than weekends. If you do not have surveys available to complete, you should focus on the websites that provide other ways to earn money as well.
It is really boring, but it is necessary for the researchers to be sure that the websites sent the survey to the right users and to be sure that the users are not providing fake information.
Usually, the time varies between 1 and 40 minutes and the value between a couple of cents and 10 dollars. It totally depends on the subject and complexity of the survey.
There are a lot of reasons for that:
1- Your profile (demographics) is not a good match;
2- The quota is full;
3- You do not show interest on the product that the survey will talk about;
4- You work in a company that the researchers think will influence your answers;
5- You started answering the questions very fast or failed the quality checking questions;
6- You have already answered or tried the same survey.
While taking surveys, you must allow all the cookies, disable ad blocks, take your time to read the questions and complete the surveys properly, make sure each page fully loads before filling out information, leave the last page of the survey open once completed for a few minutes or until it credits and wait a short period of time before trying your next survey.

Also, take notes about the ID, time, value, subject and link of the survey. Besides of that, take a screenshot of the completion page of the survey with the date and time of your desktop. This way you can send a trouble ticket to the support team of the respective website with all the necessary information to investigate the issue.
Yes. Every website provides you a referral link that you can use to invite anyone you want since they do not live in the same house.
First of all you need to know the website that you are using very well. Then you can talk about it to your close friends and ask them to sign up using your referral link. You can also make a website like me, upload YouTube videos or post your referral link on your social media, always showing the details about the website and payment proof based on your own experience, this way you can attract more people easily.
Every website has a dashboard where you can see your total earnings. Once you have the minimum value, you can cashout your earnings for digital wallets, gift cards and cryptocurrencies.
There is no limit. The money you will earn depends on how much time you will spend completing surveys and other tasks. Also, participating in contests and referral programs can increase your earnings considerably. However, you will never become rich. This kind of activity must be faced as an extra monthly income source to be done on your free time.