Hi All,

We have a well established information portal type site which has been online pretty much since the start of the web.

Back in November 2015 we completely redesigned the site and moved from a custom CMS written in the early 2000's to Umbraco. Since then (pretty much overnight) we've seen a ~50% reduction in pageviews (which seem to have come mostly from organic searches) while other metrics such as sessions, users and average time on site have remained constant or increased. Since the income on the site comes from advertising, pageviews is an important KPI for us.

All the content (10,000's of pages) was successfully migrated across and proper redirects were setup to map the old urls to the new structure from day 1.

Can anyone offer any insight or methods of analysis which may shed some light on this?

The only thing I can think is that the number of indexed pages has dropped by around 65% (in Google at least), while the number of actual content pages hasn't changed - in fact its growing as 20 - 50 new pages get added each week. One issue is that the "old" site never sent a 404 header for not found pages. Instead it would redirect to the homepage appending the filename to the url and returning a 200 code. These pages (along with every search ever conducted on the site and most server errors in a similar manner) were then indexed. Could this be a contributing factor in the drop in traffic?

Thanks.