Gmail comes with small cheats that other free email services are reluctant to provide. All of these tricks are meant to be used in the situation when you, the gmail user, is a recipient of an email, not vice-versa. Also these are against the standard industry practices, and as such, you should take it with some grains of salt; Google, in theory, could drop support of these features in the future.
Putting Dots(.) in the Address
Oddly enough, Gmail doesn’t see dots. So sending an email to ‘firstname.lastname@example.org’ or ‘email@example.com’ is no different from ‘firstname.lastname@example.org’. You could potentially use this feature to make your name more legible on the business card. For instance, you could go by doe.j instead of doej, which I can guarantee it will a subject of some interesting discussion for some as to your possible Scandinavian origin.
Personally I found this feature nothing more than a fancy bling on the Gmail, considering this appears to be sort of a bypass fix, rather than an actual systemic design intended for accessibility. Considering the size of user base Gmail has to work with, some senders could fall under the impression adding a dot in recipient address can make difference. Returning these mistaken emails alone would be a huge traffic.
Again, the point is, putting a dot in your gmail address will not affect who receives the said email. You could use this trick to emphasize or to link two names, –much like j.doe– but make sure this trick can only work when YOU are the recipient.
Putting Plus(+) at the End of the Address
This one is my personal favorite. If you are concerned which service provider is selling your information, you could easily make use of this feature to your advantage. When you are signing up to any kind of subscription, all you have to do is simply add a marker at the end of your address, proceeded by the plus sign. Say I am signing up for a magazine, all I have to do is simply add plus, followed by keyword, ‘mag’ at the end: ‘email@example.com’. And I would still get the email, but the recipient address on the email would have the marker for me to identify.
You could also use this feature to fool some of the nonsensical geo-locks. Some of the online app stores, social networking services, streaming services, and financial services ask you to open a new account per region. Now, you are already using ‘firstname.lastname@example.org’ for everything, and now the same service is asking you to open a new account for a different region. In that case, all you have to do is simply add plus sign, and a keyword to identify followed by it.
For the record, some of the edgy services pick up Gmail comes with Plus trick. But in truth, considering how easy it is to simply open a new account on Google, I must say their attempt is quite ludicrous.
All of these tricks could make using Gmail worth it. But again, use it at your discretion Stay on top of your own device, and don’t let it lead to your demise. Google can easily decide to stop supports for these tomorrow. These are neat tricks, which I would love to see in my work email, but almost always never happen.
updated Dec 17, 2017: edited for better readability.