Both Google and Facebook have acquired promising start up companies in moves analysts say are driven by the need to take on skilled staff.

Google announced today it has purchased 15-month-old daily deal site Dealmap, for an undisclosed sum. The search giant launched its own daily deal service, Google Offers, in May, after having a US$6 billion bid for rival Groupon turned down last year.

Two weeks ago Google's new social network offering, Google+, purchased social network start up Fridge, then promptly shut it down.

Meanwhile, Facebook has purchased interactive book design firm Push Pop, also for an undisclosed sum, and also largely for the skills of the staff.

Analysts have dubbed the policy acqui-hiring, saying success in the free market can often be a better indication of talent than credentials and degrees.