Remarketing within Google is a specific use of the wider Google Display (formerly content) network (learn more about the content network). When remarketing is set up & configured it allows you to target people that visited your website with adverts on other website which have opted into displaying adverts from the Display Network. Check out this video from Google which outlines just how remarketing works...
The answer is yes but as with everything in life it comes with a few 'but's"... It has to be configured correctly, what I mean by this is:
You HAVE to define & segment your audience
You have to be intelligent about how you use it, take the time to consider your options
Remember that this isn't your only tool for remarketing
Clearly being able to target people that have already been on your website in other areas of the web is going to be a powerful way to re-attract traffic and increase your brand exposure. Consider the following questions before you decide to create your campaigns:
What made them leave your website in the first place? price, lack of content, out of stock products...
Have you fixed the likely issues?
Are there clear sections & journeys on your website which will help you segment your audience?
How could I use it?
The ideas below obviously don't apply to every website but I hope I have covered enough so that at least one is relevant for your website. If you would like some further help why not ask me the question on the Smart Insights LinkedIn discussion group.
Product page exits - Offer a discount or free postage in your adverts for the specific product
Checkout exits - As above
Recent Purchases - Ask for feedback in return for voucher or freebie
Recent Purchases - Upsell / On sell adverts
Recent Purchases - Ask for referral in return for voucher or freebie
Viewed promotions - Reminder of promo end dates
I am sure there a million & one other ways of using this service, but hopefully the above will get you thinking on how you can implement in your business?
Are there any Privacy concerns when using this service?
Unless you can guarantee that seeing your advert on various websites will genuinely add value to the user or that the user only uses the net once a week I struggle to see why you would set it more than 7days?
Some more advice / quality reading on Google Remarketing: