A previous firm I worked at was bought as part of a roll-up (market segment consolidation). If you're the firm that they're rolling all their acquisitions into, that's great & exciting. If you're one of the roll-ees, not so much.

They bought us not for our technology but our customer base. They intended to convert them all to their other firm's product. Little did they know that a lot of our customers had left the other firm for us because we treated them better.. So what happened is in addition to the back office staff & sales staff being laid off, they laid off the developers & testers too (they kept a few managers for a year for continuity). I realized this when the folks they sent to town refused to go to lunch with us in an rather awkward moment.