The title tag is one of the most heavily weighted on-page factors in Google's algorithm. It is the one place where a few slight changes can result in huge ranking increases. So it makes perfect sense to me that Google would apply a temporary "penalty" to a website that changes them to frequently (or at least having that be one of the many triggers) - making it tougher to game the system. This is also referred to by many as the Google Sandbox Effect. A term you are probably familiar with.

If no such penalty were in place, we'd have a bunch of people always changing their title tags in an effort to out-optimize their competitors. And if everyone was doing it, it would be a lot like a dog trying to catch it's tail. Which would just be a lot of wasted efforts, IMO.

You can almost always expect a slight drop in rankings after you initially change your title tags, but normally, depending on how active your site is, they will likely come back within a few days to a few weeks.

From my experience it takes about 4 to 8 months to work you way out of the sandbox for this particular type of penalty. Other penalties may be longer or shorter.

I just had another one of my nearly abandoned web projects recently work its way out of the sandbox.

I strongly suspect the Sandbox effect also applys to Google maps as well, however, I believe the triggers and penalties are applied much differently. Either way, pick an appropriate title and stick with it.

For the organic search results I don't recommend changing your home page title tag more than twice in a six month period, however, I don't know what the exact number is. If you need to change them more often than that, then I suspect you doing a bunch of stuff wrong.

If your site is in the sandbox, then I recommend just doing what you normally do to properly increase your rankings (content, links, patience, etc.), just stop playing with the title and meta tags for awhile. A long while.

You could also try requesting re-inclusion or changing domain names entirely, but that really depends on your particular situation. I wouldn't expect to get much help for Google if you're not a major brand name.

I'd love to hear your experiences and thoughts on this.