This extension does NOT effectively or accurately do what it claims -- the exaggerated claim masks what it really is: A universal tracker and data collection app for everything you see and do with Firefox. You have to provide an email address to use it! I ran a test based on a purchase I made the day before: I found a specific SSD drive on Amazon with their best price of $74.50 but then looked around and found it on Ebay for $68.00 and bought it there. So today, after installing this extension, I ran the exact same purchase test on Amazon: After the $74.50 price came up on Amazon the Capital One Shopper did NOT pop up with the price of $68.00 on Ebay (or anywhere else).

The access permissions for this extension enable it to collect your PERSONAL, NON-ANONYMOUS data on absolutely EVERYTHING you do in Firefox in real time from all open tabs and searches. Then, by its own admission, immediately sends this personalized data back to Capital One for their use and storage (and ostensibly so they can find you "like, the absolute bestest price EVER!") Sure the user agrees to this during installation, but how many people realize just how invasive it is and that it really does not do what it claims very well? This extension crosses the line into serious privacy abuse and seems like it may even present a security vulnerability to the Firefox platform.

Do not install it and open the account they require for it to operate "just to give it a try" because the second it becomes active in your Firefox it will immediately grab everything it can find and send it to Capital One with your name and email address on it. And they don't let you change the email address you give them when activating the extension.

Gives often alternatives that do save some money. Sometimes the tradeoff in the offers don't make worth the small savings offered.

I don't understand what this is supposed to do. They say it saves you money. When I downloaded and tried to use it, it literally doesn't do anything. The extension is so poorly built that it can't even recognize an authenticated session within the browser - which means you can't use it for anything. I am using a fresh install of Firefox in a brand new install of Windows so it's not my cache, history, etc. as I have none.

Don't waste your time with this and ignore Capital One's claims and advertisements that they are better than Amazon (LMFAO). Capital one is a scrub compared to Amazon and this extension proves exactly that.

This app appears to be nothing more than a pop up spyware advertising box that modifies your searches for overpriced Scamazon purchases and is a waste of time.
It is not accurate and appears to be a paid partnered advertiser for Amazon. Everything I Searched for lead me to the Amazon website, even though they were more expensive that other sites. One item that I searched for showed that the item was $4.29 on Amazon and $8.39 on Ebay. The only problem is they forgot to mention the $4.99 for shipping on Amazon making the actual price $9.28.
It pops up on pages where I'm not trying to purchase anything, blocks listing views on websites and has no close button to dismiss their app.
Also it's constantly wanting me to sign in so I can use their Capital One credit card to make my purchase, of course off of Amazon. Sorry I've been ripped off way to many times with defective Chinese knockoff garbage from Amazon, and I refuse to buy anything from them making this app totally useless to me.

Worst add-on ever.

Aggravating nuisance. As much as I would like to use this thing, it is more annoying and rarely worth my time and patience.

It pops up continuously, even after clicking it away. Barely three seconds pass and it pops up again - over and over. When you are trying to read about a product, you don't want a large block of print from some poorly executed extension continuously getting in your way!

It's footprint is large, you cannot see behind it, and there does not seem a way to control how or when this pops up. And if there is one, then it is hidden from easy access. That and its occasional problem with asking me to sign in, only to say that my account doesn't exist, or worse... hang. Because of this happening the fist time, I hadn't realized what was going on, so I inadvertently created a second account, thus there are now two different accounts accruing credits instead of just one. It all depends on which account will allow me to sign in that day.

I am not about to chase after, or spend time trying to get help to correct this. Either an extension works the way it should when released, or away it goes.

Just saved me over $17.

Getting two stars since it said it could save me $50, but when I went to the site, it was going to charge me $20 more. WTF, Capital One.

This has been the WORST experience for me. I just now finally found how to get rid of this bug ridden piece of rot that continuously pestered me to sign in and would never allow me to despite trying for the sake of making it leave me alone! Now I have removed it for good and I hope this was their intended reason for driving me up a wall all this time. There were no 'rewards', it was not useful, it was as far as I can fathom an artifact of another app I once used successfully that was taken over by Capital One. Bad Bad Bad, run now while you can. Install this and remember my words here because you too will regret it. Their last parting shot was "Giving up that easily?" Really?! If I could have, I'd have put a bullet through the head of this program but I couldn't figure out where it was coming from. Now I have, you are forever gone Capital ONE, buh bye bye bye!

It works for me, it has saved me quiet a bit of cash and, helped others with it. It really looks like all those fly by night apps but, it is not. I find the communication to be quick and understandable, always. This is not someone that will fail and disappear. This is Capital One.

App is in an intrusive, buggy, pos. It pops up on pages where I'm not trying to purchase anything and has no close button to dismiss it. These are amature UI design mistakes that massive companies, like CapitalOne, should never have.

Numerous times I felt I didn't get my rewards. Finally tracked a bigger one for a Garmin watch. Didn't get my reward. Unsure why, won't bother contacting them.

For eBay it shows 5% off in the popup but on their page it shows 0.5%. Misleading.

Just a shady experience overall at this point.

Avoid this kind of useless shop-savings extensions that in facts can spy what you are looking on the internet, it's just collecting informations on you to profile you and similar customers to finally target ads/products/services. That's desguished spyware in counterpart to provide you a pretended nice service for free.

And just about the service provided: this kind of extensions (lots of similar exist like this one) can modify the webpages on-the-fly and also can censure some parts or search results to guide you to buy to a specific shop... instead of a concurrent. And guess who is paying the extension editor to do that? Sellers?
Just look at what this extension is requiring at the Permissions part...

Mind again before adding browser extensions!

You can maybe find coupons that still work about 30% of the time if that. Do not bother with using this if you think you'll get rewards from your purchases outside of the standard 1% or whatever your card offers. I've not received a single penny from the rewards offered through the extension. The only redeeming part of the extension and CapitalOne Shopping itself is the price comparison except when it inevitably links to a used product on ebay.

Coupons codes are outdated. "Cheaper" alternatives are actually more expensive with shipping. Used for two months everyday..

Hope you never have to change emails for any reason. They will just keep your rewards that you supposedly earned. Of course, after reading other reviews, you never get hem anyway!

I love Capital One