It's a wide-spread marketing technique that seems to have been around forever- selling products for £1.99, £9.99, £19.99, instead of £2, £10 and £20.

Presumably the pyschology is that submliminally £99.99 seems disproportionately closer to £99 (or £90) than £100 does.

But surely the technique is so utterly transparent and consumers so wary of marketing techniques nowadays that it is completely ineffective. And worse, by doing it, you risk detering potential customers by coming across as deceptive or dishonest.

  • 3
    @Brendon I don't understand. Why does that make you wary?
    – Urbycoz
    Jul 24, 2013 at 14:55
  • 1
    Maybe there's real data out there, but I have the same take as you. I find whole-number pricing rather refreshing and more 'honest'. A prominent example of this is jcpenney.com and their new $10/$15 pricing scheme.
    – DA01
    Jul 24, 2013 at 15:14
  • Here's an answer to a a possible duplicate question. The other question focused on donation vs paid though, and got a rather dubious top answer
    – Ben Brocka
    Jul 24, 2013 at 15:23
  • @Brendon Iceland (UK frozen food store) prices most things in whole pounds. I've never been wary of them. Jul 25, 2013 at 7:29
  • Aside: One physical retailer in the UK uses the last right digit of the price as an indicator to staff as to the status of the stock (ie 19.99 stock is different from 19.95 stock) I've a recollection that staff could choose to discount one stock class with a customer if the customer haggled but not the other.
    – PhillipW
    Jul 25, 2013 at 8:36

7 Answers 7


The psychology behind the $99 was explored in depth in Priceless: The Hidden Psychology of Value, which if you ask for my humble opinion, is a life-changing book.

9 is the Magic Number

A price such as $99, or $14.95 are known as charm price. Research suggests that the most effective charm price is that ending with 9. A University of Chicago/MIT research (Eric Anderson, Duncan Simester) with a mail order company yielded most sales when an item was priced $39 (despite $34 being cheaper!):

  • $34
  • $39
  • $44

Mental Rounding

The obvious reason for the success of charm prices is mental rounding ($99 is in the 90s while $100 is in the 100s). But both strong proof to people's ability to grasp magnitude and the fact that more people bought the $39 product than the $34 one suggest that the mental rounding assumption is very partial, if not neglectable.

It's a Bargain

An alternative theory is that charm prices are seen by people as sale prices or a bargain (which does not suit all businesses, like luxury merchants; also such price can also be linked to hard-sale).

Easily Cheaper

But studies into consumer choice and trade-off contrast seem to provide the most solid explanation, albeit a surprising one:

When there are many hard-to-evaluate options, attention wanders. It is drawn to easy comparisons, to options that are clearly superior to another, even if the difference is slight. The imagined round-number price becomes a foil for the 99-pence price, bathing it in an unaccountably alluring glow. (Priceless: The Hidden Psychology of Value, William Poundstone).

In other words, we see these prices as attractive because the brain finds it easy to see how they are cheaper from the round-number price.

  • @lzhaki I didn't say I thought that it appeared cheaper. I said that "presumably that is the psychology".
    – Urbycoz
    Jul 25, 2013 at 8:08
  • Yes. Sorry if the phrasing suggested you thought so. I, like you presumed the same.
    – Izhaki
    Jul 25, 2013 at 8:50
  • 1
    I conducted an experiment with 6 prices around $1900 including 3 magical ones and the majority chose the cheapest, which wasn't magical. Nov 30, 2013 at 12:52

Izhaki's answer pretty much covers everything related to the UX and psychology behind the x.99 pricing. But there's more -- the x.99 pricing is the key to a killer marketing strategy -- figures for discounts and offers are cleverly crafted numbers, which are almost always impossible to reach without buying one extra item. Why? Because discounts are offered on figures such that products total to prices always just a few cents shy of reaching the nearest amount for which a discount may be applicable!

Here's a real life example:
Offer on purchase of over 2000
Products for which the above offer was applicable were all priced at 99.90, 199.95, 499.99, 999 etc. Even if the customer were to buy 20 items averaging 99.99 each, he'd only reach 1999.80, which isn't enough to get him the offer! And wallah! This necessitates the purchase of that one extra item (of whatever minimum cost possible), to make that discount figure!

Furthermore, even if the discount were applicable on a non-multiple of 10 figure, like:
Offer on purchase of over 999
the only way to attain this in a single shot would be a purchase an item priced at 999, 999.95, 999.99 etc. But of course, the sales team already knows this. And the nearest priced item one might find may be something like 995.95! You do the math! :)

As a side-note, if you consider products were to be priced at round numbers, such as 10 or 20, then to make the above strategy work, discounts would need to be targeted at figures like 1001, which would make the trick obvious! ;)

UPDATE (21-Nov-2019):
Here's evidence of a ₹500 off on ₹1000 discount coupon for a store where the prices all end ₹1 short, such as ₹499 and ₹999. The least valued item at the store was at ₹299, necessitating its purchase to avail the coupon, thereby diminishing the effective discount.


500 off on 1000

Example products on sale:



I have a book somewhere (don't remember which, need to look it up) which explains that it's more important to have a short number, rather than low. $9.99 looks longer (larger) than $10. Then again, $10.00 looks larger than $9.99

The same book suggested a whole different approach: If you have a product of $10, introduce another product of -say- $12. Even if no one buys the new product, it makes the $10 look cheap. I took that advice and revenue shot up 20% or so. Amazing...


$19.99 sounds cheaper than $20. Although most people can tell that they're pretty close, it's still a marketing strategy that some people fall for. The human brain will sometimes register $19.99 as $19, instead of $20.

· http://www.marktaw.com/culture_and_media/1999vs2000.html
· http://answers.yahoo.com/question/index?qid=20081223014045AA0ufcV
· http://www.funadvice.com/q/why_the_prices_always_end_19_99_instead

Read some of these, they seem to be pretty reliable from my (little) marketing experience.

Fun fact: It doesn't matter in Canada anymore, $19.99 rounds up to $20 if you pay cash because of the removal of the penny.


Here is a graph from the Wikipedia page of Psychological Pricing. It is self-explanatory. image description

  • 2
    1997 was almost twenty years ago! the Web, and ecommerce was very different to how it is today. Not sure this can be used as a reliable resource.
    – Midas
    Jun 1, 2016 at 16:11
  • @Midas +1 for pointing out that. However, isn't that this is a psychological issue, rather than an issue of UX or web technology?
    – Ooker
    Jun 1, 2016 at 16:52
  • @Midas the practice arose in the late 19th century according to the same Wikipedia article, which means that such pricing had been around for a 100 years before the study was done.
    – icc97
    Jan 7, 2018 at 17:18
  • 2
    This table shows how many people do it. The question is asking for why people do it rather than how many.
    – icc97
    Jan 7, 2018 at 17:21

Just to add to all the points made here: there's a study out there that concludes that prices ending in 0 increase the perception of quality, while prices ending in 9 increase the sense of value: http://www.sciencedirect.com/science/article/pii/S0010880401900084


I have a personal theory that digits with declining decimal values appear cheaper than .99. For example 9.87 is a better looking price than 9.99, not because there is a difference of 0.12 but because .87 gives you an impression that cost is going down while .99 shows the same and two highest integers together. Likewise 4.51 vs 4.43 feels soothing.

Out of my experience, I would suggest you not to use 9.99 or 99.99 prices ever. Give user a sense of "saving" or "not being 100". When price is 99.99, we know we will be paying exactly 100 as no one would return you 1C but if the price was 97.21 then you know its not 100 and rather you will be "saving" 3 dollar. I would also suggest you to use 97 instead of 98 because with 97 you project the feeling that price is 95ish and user would save 5ish dollars. With 98, you tend to think price is 100ish and sense of saving is reduced further.

  • 4
    "as no one would return you 1c" - I don't know what the norms are in Australia, but for sure you expect to get the change you are owed in the UK, even if it's just a penny. And all the till operators will do so without thinking twice of it. Jul 25, 2013 at 7:32
  • Here in Ukraine cashiers widely "forgive" if customer cann't find a coin and some customers leave a small short change. It is up to 5 kopeek that is 0.6 c. Jul 25, 2013 at 9:39
  • Here the smallest working coin is 5c. Jul 25, 2013 at 10:21
  • If the smallest coin is 5c then prices should all be multiples of 5c. You can't ask someone for part of a coin. How did that happen?
    – user67695
    May 12, 2017 at 17:26

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