One thing every website, every e-newsletter, every sweepstake, and every freebie that you sign up for is going to require is a valid email address. The reason they want your email address is so that they can send you emails. And many of them want to send you LOTS of emails.
This is why it's important to have more than one email address.
There are plenty of places to find free email accounts--Gmail, Yahoo, Outlook/Hotmail, your internet provider, etc. Take advantage of that opportunity to open as many accounts as you need to organize your email to suit your specific needs.
If you are only interested in signing up for writing sites, junk mail should not be an issue. Most writing sites usually only contact you about payment. Others allow you to opt in to receive notices about certain issues. But payment emails are something you don't want to miss, so when signing up for writing sites, it's wise to use the email address where the important stuff, like bills and bank statements, goes. If you are going to be paid by PayPal, it should also be an account tied to your PayPal account. (More on that in a future post).
One email address might be sufficient if you're signing up for writing sites only, but it never hurts to have one or more extra.
If you intend to get paid more than an occasional 50 cents for taking surveys, then you may want to set up an account just for surveys, or for surveys and other things that you want to check on several times a day. The ratio of surveys you are offered to surveys you actually qualify and are paid for is very low. The invitations that land in your email box should theoretically be the ones most likely to match your profile, so you want easy access to them so that you can respond to them as soon as possible before all the slots in your profile group are taken. You don't want the notice to get lost in a long list of other mail.
Then there's the other stuff. If you like to enter sweepstakes or sign up for freebies, you already know how much junk mail that can sometimes generate. Even if the site doesn't share your address with their "partners", you could end up with multiple sales pitches in a single day from a single site.
"Offers", either free (as in not supposed to cost you anything) or paid (as is fork over your credit card info), are a big part of some "Get Paid To" (GPT) or "Paid to Click" (PTC) sites. All of them require an email.
The free ones are basically a trade-off. You give them your email address in exchange for a token amount of points. All of them are going to generate some email. Some of them are going to generate a lot.
As of this writing, I haven't had much extra mail from the GTP sites I have signed up for themselves. Some of the offers, on the other hand, send one or more emails daily. I still have many more sites I want to sign up for, so I expect the junk mail to increase.
Most of the time, you can unsubscribe without any more hassle than clicking on the unsubscribe link and following through the instructions. It's not difficult, but it does take a little time. If you multiply that by a lot of sign-ups, it could take a lot of time.
So, it's a very good thing to have a separate account for anything that could be spammy: newsletters, sweepstakes, contests, online retailers that you aren't currently placing an order with, organizations that offer you information, etc. If it turns out that the communication you get is something you really want to receive, you can always change your contact information later.
As far as GTP and PTC sites, it should be okay to sign up for the reputable ones with a regular account tied to your PayPal (if they pay via PayPal). I haven't had enough experience with some of them to know. If in doubt, use the junk mail address. If it turns out okay, you can change it later easier than you can unload the junk mail from your regular account should they turn out to be spammy. Just be sure to make certain that you sign up for offers with your junk mail account. Sometimes they automatically fill out part of your contact information on offer forms, including the email you signed up for the site with. Watch out for that and change it.
When signing up for a junk mail account, choose one with a good spam filter. Just make sure to check for confirmation emails after signing up for something new. You will need to respond to these to confirm your account, and you may need to hunt them down if they are sent to the spam folder.
What I Do:
I'm preaching from hindsight more than practice, but I am in the process of taking my own advice. I have a "good" account that I keep as private as possible. This is my main PayPal email, and the account I use for important things. I've opened a new junk mail account for many of my new sign-ups.
And then there's my "regular" account.
This was formerly my primary account for almost everything, which is how it ended up being clogged with a lot of junk. I'm in the process of reclaiming it now for the things I want to see daily, such as surveys and emails from stores and websites I use daily or weekly (got to have my free downloads from Book Shout, Kroger, and Saving Star!), and sites that I trust but don't want to give my good address to. This is my secondary PayPal address. I'm in the process now of moving other things over to either my good account or the junk mail account.
As I see more organizational needs, I'll probably open one or more additional accounts in the near future. Right now I'm noticing two different types of emails in my junk mail account that I'd really like to separate. I'm considering another account for things that are somewhat important but that I don't want in my regular account.