Just when you thought the buying spree of social game and app companies with diminishing traffic and valuation numbers by large companies hoping to buy into the market ended when Disney bought Playdom last week, think again!

Techcrunch and Inside Social Games are reporting that Google is buying Slide for $182 million.

For Google, this is yet another move to try to play catch up to Facebook. Google is reported to have invested $200 million in Zynga and bought a game company Labpixies earlier in the year.

For Slide, this appears to be a good deal considering their recent downward spiral. According to Inside Social Games, Slide’s games and apps (Top Friends, SPP Ranch!, SuperPocus) have gone from generating 48 MAU’s in March 2009 to 14.7 million MAU’s this past month. Comparing Disney’s $563 million purchase of Playdom with their 40 million MAU’s, and it looks like Google over-paid for a long shot.

Apparently, Slide’s founder Max Levchin once said that he wanted Slide’s exit to exceed the amount his previous company, Paypal $1.5 billion sale to eBay.

$182 million is way less than $1.5 billion but more than Slide was probably worth at this point, so he should be happy with a Google acquisition (assuming the ink on the contract has not dried and someone from Google is not reading this and every other blog telling them they way over-paid).

For social game companies looking for an exit (i.e., all of them), this acquisition is good news. There is still hope to sell out after Disney and Playdom. It’s also a lesson, as well. Slide’s valuation last year was $500 million. Sometimes its better to sell for less as you are rising than risk falling over the peak and selling for far, far less.