I've worked for companies that got acquired and also acquired other companies. Year 1 is usually nothing and things stay the same unless there is some serious fat that needed trimming. The interesting years are 2 and 3. That's when the parent company tries to optimize things (e.g. streamline the sales force), create synergies, etc and you start seeing the changes. Depending on where you are in the acquired company, i…
The process was remarkably similar even though they were quite different businesses. Middle management was purged quite quickly, shortly after that all the value creators walked.
In both cases the purchaser ended up with a customer database and some residual support revenue. This may have been their expectation all along, I don't know how the figures looked.
I've read somewhere that most acquisitions don't deliver any value for the acquirer. This is why their share price usually falls on the news.