What Has Been Your Worst Optimization Tactic?

[espmartin]

Blackhat SEO works. Not for very long, and it's plain wrong to do, but some
(if not all) of those optimization tactics have given top SERPs and traffic to
websites. And when you get caught by the SEs, your penalties
will be very harsh. Delistings and such!

So besides purposely using blackhat, what have been some of
your honest mistakes you've made in SEO, that you want to share with the
rest of us? As we better learn from mistakes than success!

[smeagain]

Once (about 12 years ago) I placed a temporary link on a punctuation mark to allow my client to view a new directory on his site prior to going public. This was catastrophic and that page fell like a stone and after I realised what was happening and rectified it, it took 2 months to recover.

In those days most webmasters (including me) did not fully understand the measures being rolled out by the major Search Engines to combat spam and they didn't tell us either. Not only did this new minefield take most designers by surprise, but also the Search Engines were very Punitive with their responses sometimes even banning an entire site indefinately.

Very embarassing and I never forgave myself, but that motivated me to invest many hours running experimental sites to discover as many No No's as I could think of testing for.

These days of course, the majors publish Guidelines and dislikes for all to see, so we have no excuses. If we try it on, we must accept the consequenses when we get found out.

[kineticdc]

I referenced a competitors web site mistakenly and my results dropped like a stone in a cold deep well. When I found the mistake my site recovered quickly.

[espmartin]

One of my mistakes, though it was NOT my fault it happened, was to separate a few of
my sub domains onto their own IP addresses (separate class C networks! ) - but once
I moved hosting companies (check out my review in the review your hosting section),
I lost those IPs.

Problem was, I had offered blog posting on unique IPs, for which I cannot honor anymore