Indexed page count dropping, old site, unique content, aged links?

[syragon]

I have an old site (3-4 years old) with plenty of unique content (at least 30% of the site is unique, the rest has info from the manufacturers)

Most links have been around for years

Recently I added a couple hundred subdomains for new categories within the site

I also added a snippet on all the product pages that shows off site blogs related to the product

I have noticed the page count dropping over the past week.. first 50, then 100, then 150...

Is this happening for anyone else?

I went and checked all my inbound links - found some that looked spammy and had them removed...

I also just removed my pre-existing link exchannge directory on the site, as a precaution.

Am I under a penalty? My inbound links have increased recently, but the site is old and it should be fine. Should I just ride it out?

[tedster]

If you are under penalty you will see a lowered level of traffic.

I assume you are using the site: operator to see the number of indexed paged. Many people report strange numbers with the site: operator. It is nothing to be overly concerned about UNLESS your traffic is drying up too.

I added a couple hundred subdomains

That sounds risky to me, especially as time goes on. How many urls for the average subdomain?

30% of the site is unique, the rest has info from the manufacturers

That is one reason why you might lose indexing - on pages that are only the manufacturer's information.