What happened to Google Shopping merchants on March 16?

Did your traffic decrease on March 16?

[CPC_Andrew]

Lately we have been watching many changes from Google's search algorithm including the Panda, but one that hit a lot of our clients was on the 16th. Google Shopping (Google Product Search) traffic dropped sharply for certain retailers with no apparent reason why.

It's not clear if Google was adjusting the algorithm for whatever reason, but where could those clicks have gone? Some of our clients had a decrease of 50+% in clicks that day which slowly rebounded, some to their previous levels but some that are still lower than usual. Forum members were impacted as well:

[webmasterworld.com...]

Some questions I have:

Where did the clicks go on March 16?

Did you experience a notable traffic increase from any different Google channels on that day?

What are you doing to combat this click drop?

[IanTurner]

Hmm we have seen a decline since mid April - when we added our delivery charges into the feed - some competitors still haven't added theirs so I would expect that when everybody has to have delivery charges we will see an increase again.

We didn't see any change on March 16th

[CPC_Andrew]

As long as your final price is competitive you shouldn't see much impact in overall revenue. some of our clients had no change as well, while others made gains, but a large portion had major drops too.

When separating our 80 clients into four groups based on how hard they were hit traffic wise on the 16th, group 1 lost an average of 69%, group 2 lost 22%, group 3 gained 10.5% and group 4 gained 24%.

For the entire month (comparing March 1-15 vs 16-30), group 1 lost 51%, group 2 lost 11%, group 3 gained 3.5%, and group 4 gained 17%.