Here, in its entirety, is the report as penned exclusively for this publication by Dritan Suljoti, cofounder and chief product officer of Catchpoint.

The retail industry faces intense pressure and scrutiny in Q4, as the drastic increases in web traffic during the Thanksgiving/Black Friday/Cyber Monday weekend can wreak havoc on ecommerce systems. 

To complicate matters, the huge sales and increased marketing demands during this timeframe also put IT teams under strain, as page sizes tend to increase due to additional high-res images and third-party tags. As we have preached many times in the past, the heavier a page is, the longer it generally takes to load.

Therefore, one would expect to see a significant increase in the average mobile retail page size in Q4, particularly after multiple quarters of page size and corresponding load time increases leading up to it. 

Yet surprisingly, we only measured an average 2.2 percent page weight increase from Q3. 

What is more, the average mobile retail Webpage load time actually decreased by more than half a second, down from 2.99 to 2.44 ? an 18 percent drop. Note that these are just backbone measurements, so end users could still have experienced longer load times due to the strain that is typically put on mobile networks during high traffic periods. 

At the very least, these metrics show that IT teams were very effective at optimizing their service delivery and successfully improving the performance factors that were actually under their control.

The best performers this past quarter were, not surprisingly, the ones who managed to keep their overall page sizes down and limit the number of third-party hosts that must be called to load the page. This quarter?s top performers included some regulars in the top five (Grainger, Gap, Amazon), but also featured Home Depot as the new champion on top.

Top performers (mobile retail Webpage load time):

1. Home Depot

2. Grainger

3. Gap

4. Amazon

5. Costco

Much like retail, the banking industry saw similar trends in Q4, with the average mobile banking page size increasing from Q3 ? a 6.9 percent page weight increase. 

Also similar to retail, banking saw an increase ? albeit less of one ? in the average number of third-party hosts and objects on the page. However, due to the banks? performance optimization efforts, the pages still managed to see a sizable improvement in mobile page load times (9.8 percent faster), delivering an average mobile banking Webpage load time of 2.06 seconds. 

Banks need to be wary of the increase in third-party hosts. Adding more hosts on a site can not only increase latency and load time for that page, but it can also increase end-user perception of potential security risks. 

In terms of the top performances this past quarter, TD Bank, US Bank and Wells Fargo remain in the top three spots, with each showing faster load times despite slightly higher page weights. 

Rounding out the rest, Citibank and Chase are returning to the top five after getting bumped out in Q3. While both took advantage of several competitors? sites slowing down from the previous quarter, both Citibank and Chase saw significant load time improvements as well, so their presence in the top five is well deserved. 

Citibank?s mobile Webpage load time improved by 20.7 percent, while Chase saw a 17.5 percent improvement.

Top performers (mobile Webpage load time):

1. TD Bank

2. US Bank

3. Wells Fargo

4. Citibank

5. Chase

Keeping the pattern going, the travel sector saw the same industry-wide trends as retail and banking in Q4: increased page weight ? on average, sites were 10.2 percent heavier ? but improved mobile Webpage load times. Mobile sites downloaded, on average, 4.3 percent more quickly than in Q3. 

The travel industry?s mobile page weight increase was greatest of all three and its load time improvement was the lowest.

Travel often suffers from the same challenges as retail, with high-res images and sales advertisements deemed necessary to attract users. Of course, these page elements also tend to drag down performance of those sites, leaving IT teams stuck trying to find the balance between items that draw more users to the site but degrade the performance of the site once they get there.

As in past quarters, the performance of one specific mobile airline site dragged down the average industry mobile Webpage load time (2.66 seconds), but other sites deserve praise for their work at improving their customers? mobile experiences. 

Most notable was TripAdvisor, which claimed second place for the second straight quarter (perennial champ Google Flights remains #1), and for the first time got under the one-second mark thanks to a whopping 33.5 percent speed improvement. 

Hipmunk showed another huge improvement with a 29.9 percent mobile Webpage load time decrease, as did Booking, which improved by 11.8 percent and jumped into the top five for the first time.

Top performers (mobile Webpage load time):

1. Google Flights

2. TripAdvisor

3. Hipmunk

4. Priceline

5. Booking

The obvious theme in the fourth quarter of 2015 was the performance optimization techniques that were employed across the different industries. 

The previous two quarters had seen slower load times and increased page weight across the industries, but this quarter saw load times drop across the board, in spite of page weight increases.

This is a great development, as it indicates that Web performance optimization techniques are really starting to take hold. 

Companies are realizing that they can satisfy their marketing and sales departments? requests for flashy elements on the page designed to attract customers and track their behavior, while still improving those customers? experiences on the site.