Dividend-paying companies typically have a fixed dividend rate, and make payments to shareholders quarterly. But plenty of companies buck that norm, and several of their alternative models actually make a lot of sense.

Few companies are actually required to pay dividends. Typically, dividends come from established blue chips with few better uses for the money. Younger companies often need that stray cash to further fuel their own growth.

However, this rule has plenty of exceptions. Insurance settlement specialist Life Partners Holdings sports a market cap of less than $300 million but it's been paying a dividend for nearly a decade. Meanwhile, Warren Buffett's Berkshire Hathaway, valued at close to $200 billion, pays no dividend at all, since Buffett is still finding lucrative investments for his company's excess cash.

The spice of life
Some dividend payers change up their payment frequency. Some companies, particularly foreign ones, pay dividends twice per year -- and they're sometimes not in equal installments. CPFL Energia of Brazil and Jinpan International of China are two examples. Other companies make their payments just once a year. Disney (NYSE: DIS) has been making annual payments for over a decade now. At Disney's 2008 annual meeting, the company explained that with more than  2 million shareholders, sending multiple checks every year becomes extremely costly.

Goldcorp (NYSE: GG), meanwhile, pays a dividend every month -- and recently doubled that payout. 

Keeping us guessing
Variable dividends are even more interesting. Cal-Maine (Nasdaq: CALM), the nation's top egg producer, pays out a third of its profits in dividends on a quarterly basis. Beginning in 2007, Progressive (NYSE: PGR) adopted an earnings-based variable model, and makes its payment once a year. Better still, Progressive's formula shares the same factor it uses to determine employee bonuses, thereby aligning shareholder interests with employees'.

These variable payouts don't put much pressure on a company. Those that have promised a certain fixed regular sum can feel a real pinch in tough times, and may have to cut back. Thus, companies may actually be paying out less than they otherwise would, in order to avoid falling short.

Variable payouts are not good if you're looking for a steady, predictable income. But for many long-term shareholders, they can make sense as a way to help increase the potential amount you'll reinvest in new shares over the long haul.

There's usually no right or wrong policy. Choose the best dividend-paying companies with strategies that suit your needs.