It is difficult to judge Blackberry z10 sales trends. However, one could use several proxies instead. Here is one such proxy from Google Trends...
This shows that there is definite interest in Blackberry z10. Looking for cities, we can see that there is also interest in some under reported areas such as Dubai, Mumbai, New Delhi and Jakarta.
We can obtain the countries/cities which are important for the trend by looking at the list.
Now if I use the Google Traffic Estimator Tool to figure out how much it will cost me to put my content whenever any one tries to find about Blackberry z10 and compare them with other keywords relating to latest hot mobile phones (Lumia 920, iPhone5 and Samsung Galaxy), we can see an interesting trend.

The blackberry z10 CPC (Cost per click) is the highest and CTR (Click through Rate) is the second highest. Now I had only included the countries that were in the trends list, as shown in the figure below. This means I had limited the search for theoretical demand to countries where Blackberry z10 is being actively searched for.

Now, I changed the keyword list to add the word "Buy " as a prefix, and the results changes quite a bit, though still indicating some interest in Blackberry. The CPC that Google is demanding from advertisers is still the highest and the CTR (number of people actually clicking through, having found some reference to buying a z10) is also the highest.
This suggests there may be enough truth in Blackberry's claims that the devices are not selling too badly.
This shows that there is definite interest in Blackberry z10. Looking for cities, we can see that there is also interest in some under reported areas such as Dubai, Mumbai, New Delhi and Jakarta.
We can obtain the countries/cities which are important for the trend by looking at the list.
Now if I use the Google Traffic Estimator Tool to figure out how much it will cost me to put my content whenever any one tries to find about Blackberry z10 and compare them with other keywords relating to latest hot mobile phones (Lumia 920, iPhone5 and Samsung Galaxy), we can see an interesting trend.

The blackberry z10 CPC (Cost per click) is the highest and CTR (Click through Rate) is the second highest. Now I had only included the countries that were in the trends list, as shown in the figure below. This means I had limited the search for theoretical demand to countries where Blackberry z10 is being actively searched for.

Now, I changed the keyword list to add the word "Buy " as a prefix, and the results changes quite a bit, though still indicating some interest in Blackberry. The CPC that Google is demanding from advertisers is still the highest and the CTR (number of people actually clicking through, having found some reference to buying a z10) is also the highest.
This suggests there may be enough truth in Blackberry's claims that the devices are not selling too badly.