It also depends on the firm's having the capacity to do highly sophisticated legal work while consistently adhering to standards of excellence.
Finally, it depends upon the firm's ability to induce the associates to adhere to wildly oppressive work hours as part of their normal schedule, such that, for example, when FB broadened its disclosure of user information there came popping out a whole series of attorneys who had (in the former cover of darkness) described themselves as "Slaves of xxx," or some variation thereof (which FB automatically designated as company names).
These firms will pay the associates anywhere from $165K/yr to start up to the high $200s, often with large bonuses tacked on to the base salary.
Why? Because it is basically a vast money-making machine for the partners who lead and manage those firms and who pull in multi-million dollar annual incomes. And the key to it is to have lots of talented bodies consistently pulling all-nighters on major pieces of litigation and major deals that such firms handle. Thus, whenever you read about a headline deal ("Skype to offer shares in IPO at $1B valuation"), you can assume that there is a small legal army at work in the background doing an orgy of billing.
For their part, the associates toil and slave in such systems for as much as 8 to 10 years in hopes of making partner so that they can one day be on the receiving end of this money-making machine.
This system works well only if highly talented young attorneys can consistently be recruited to handle the vast bulk of the billable hours involved in such work. Thus, the most precious asset belonging to such firms is precisely this pool of young talent, and they will pay dearly to get it. What is more, such associates are paid in lockstep, meaning that if one of these large firms "adjusts," the others will be quick to follow. For a nearly unbroken period over the past 25 years, those adjustments have consistently been upward. The craziness peaked in the bubble years of the late 1990s, during which the associates themselves set up "greedy associates" websites and compared notes on every dollar paid and every perk provided by their respective firms. Of course, if any firm began to be seen as out of step with what these young lawyers came to see as their entirely legitimate demands, this would be suicide for the firm involved because the top talent would no longer go there. Thus, one saw the spectacle of the most elite law partners in the nation cravenly bowing and scraping to green new grads, all for the purpose of continuing to curry favor with them for recruiting purposes.
It goes without saying, then, that the firms would easily shell out for the sorts of things described in this piece - for expensive and luxurious flights, hotel stays, cab fares, dinners out, etc. It was all part of the game, and not a particularly costly part given what the firms would ultimately derive from this labor-pool asset within their business models. During their summer internships, they would be wined and dined as law students and would be repeatedly told what a great place to work the firm was. Once recruited as associates after graduation, they were introduced to the "slave system" in spades, and the naive perceptions they had as students would often be deflated in light of a sometimes harsh reality of endless, long hours and of often harsh taskmasters who drove them with an unkind hand.
A significant part of this has to do with grabbing the students from the elite schools but the real goal was to grab the talented attorneys from each graduating class (this meant those from top schools and those from the top 10% or so of second-tier schools). The practice of law in such environments is truly demanding, and the goal was to find attorneys who worked hard, who knew how to think, and who comported themselves with the highest standards of discipline and excellence. Very few young attorneys can do all this consistently, and they are in great demand.
In one sense, however, this piece reads like it must have been written a couple of years ago. In reality, Big Law is still reeling from the latest economic collapse and the latest crop of 3Ls is still largely unemployed, with no serious prospects for improvement in sight for this particular labor market. Even the Harvard 3Ls have largely had to settle for the types of positions that, until recently, they would not even have begun to consider.
This truly is an artificial world and there is some doubt today whether it can continue to operate in its accustomed manner. Time will tell on this. I personally doubt it.