On the face of it a 13% drop in sales from 51,763 to 45,101 from the week ending the 14/7 to 21/7 respectively doesn't look to be that big of a deal but after closer inspection I think this drop is worse than it seems.

The cause of my concern lies with the fact that the higher figure for the week ending 14/7 only contained 5 days of PS3 sales at the new $499 price. If we look at the week ending 7/7, the most recent week which wasn't affected by the price drop at all we get sales of 22,102 PS3s. If we divide by the number of days in the week we get a daily average of 3,157. Now if we assume that this average would be close to that of the 2 day period in the week ending 14/7 before the price cut we get 6,314 units sold. That means that the average number of systems sold over the last 5 days of the week when the price cut took hold is 9,090 per day.

Now this is where I see this weeks sales figures being bad for Sony. If we take a daily average of PS3s sold this week we get 6,443 units.

So since the price drop came into affect Sony's average daily sales have dropped from 9,090 over the first 5 days to 6,443 over the following 7, a 29% drop!

Now obviously sales were probably higher at the beginning of the week & lower at the end so we are likely looking at end of week sales of a lot less than 6,443 per day. If the week ending 28/7 has sales following this trend then we'll see sales start at a high of <6,443 and drop further resulting in a much bigger decrease in sales than 13%.

Now I'm basing these calculations purely on vgchartz's numbers so their accuracy is tied to the sites but if close it paints a bleak picture of the impact of the product and price range Sony has introduced.

EDIT. I origionally based my calculations on the price cut occurring on the 12th of July. Unfortunately this was a mistake and I've recalculated and updated the results based on a 9th of July price drop, meaning that the scenario is not nearly as bad as I initially thought. It does show though that average dailly sales SINCE price drop between the week ending 14/7 and 21/7 is 29% which is still significant. Take from that what you will.

EDIT2. My corrected figures were slightly off due to me rushing the sums, they should be spot on now, phew!!

Weekly sales are always of, monthly they can be as much as 30% of.

Judge it by official monthly sales not the weekly guess, its way to easy to over/under estimate numbers.

was last week really only 2 days of price drop?

Actually, the price drop happened on 9th July, so there was 5 days of the $499 price and only 2 days at the original $599 price, so you're theory gets smacked on the face straight away.

Yes, the sales were down 13%...it was to be expected.

Completely off topic, but Davygee, I don't where you got your little graph from but it's pretty terrible. For the Wii, 360, and PS3 it works but having the DS and PSP on there with the way your graph jumps is pretty bad.

The DS sales in relation to the PSP sales are really skewed because of the change in ticks (2 changes) and then placing them on the same graph of the Wii, 360, and PS3 makes it even more skewed because it almost makes the Wii compare to the PSP.

After a system has been released it starts to build a backlog of people who want to buy the system but are only willing to pay a certain price which is less than the current selling price; these people are not willing to wait around forever and may move on or decide down the road that it is not worth the price they were previously willing to pay.

When a system gets a price cut the people who were in the backlog of potential purchases become highly motivated to buy the system and there is typically a massive sales spike that lasts a short period of time (usually less than a month); after that spike sales return to a lower rate more representative of the average demand for the system.

A reduction in sales should be expected, it is not a bad sign.

I wanted to fit all figures in the one chart and show it in the best way.  The easiest way to understand the graph is to actually look at the points on the axis...they are annotated and it's pretty straight forward.  Although I understand what you are saying...I didn't want the PS3 and Wii levels to look insignificant compared to the PSP and then there the DS racing ahead.

It will be a bad sign if sales are not kept at double of the previous demand, as Sony estimated.

Totally true, I expect it to tail off at around 28k and sit there until the big games arrive or another pricecut hits.

PS3 weekly sales for the last few weeks:

Week ending in 30th of June - 19.9k
Week ending in 7th of July - 22.1k
(60 GB price cut here)
Week ending in 14th of July - 51.7k
Week ending in 21th of July - 45.1k

Sony estimated doubled demand, meaning around 40k weekly sales. It's getting really close to it already, after two weeks. Doesn't look good for their expectations...