It won't be long until many people run out of PlayStation Plus--whether it's users that took advantage of the free month offered by the "Welcome Back" program, or early adopters that bought a subscription when the service was introduced a year ago. Either way, Sony wants you to continue using Plus, and is hoping that its "Birthday Bonus Months" campaign will entice you to resubscribe.
From now until July 11th, everyone that purchases a 3-month extension of Plus will receive one bonus month. If you get a one-year extension, you'll receive 3 bonus months. Essentially, you can get 4 months of Plus service for $18, or 15 months of Plus for $50.
The PlayStation community has been keeping track of the content released on the PlayStation Plus service, and has determined that $460.43 of content has been given for free since the program's inception. There have been 14 free PSN releases, 11 PSone classics, and 22 Minis offered to subscribers. Obviously, once a subscription lapses, none of this content will continue to work.
For some, PlayStation Plus has been a tremendous value, given the sheer volume of content offered to subscribers. Others, however, have been less than interested in the games Sony has been offering to members, and wish Plus offered more services akin to cloud saving.
Continuing a subscription will extend the time you have left to your existing subscription. The easiest way to check on how much time remains on your account is to find content you've downloaded for free, hit Triangle, and see when the content expires. Another way is to go to Account Management -> Transaction Management -> Services -> PlayStation Plus. Remember, due to the service disruption, your subscription may end much later than you expect.