One of the best things about great dividend stocks is that many of them actually increase their dividends each year. In other words, investors' dividends as a percentage of their initial investment can actually grow over time. With the New Year under way, here are two tech stocks investors can almost certainly count on to raise their dividends this year: Microsoft (NASDAQ:MSFT) and Apple (NASDAQ:AAPL).

Today, Microsoft pays out a meaningful dividend yield of 2.7%, or $1.24 per share. But investors should expect this payout to continue to rise. Not only does Microsoft's dividend history suggest this will happen, but the company's fairly conservative payout ratio -- its annual dividend divided by its annual earnings -- of 43.9% shows there is still room for increases. Further, analysts, on average, expect Microsoft's earnings to continue to grow 6.6% annually for the next five years, giving the company even more breathing room to increase its dividend. Microsoft has been a popular dividend stock for years -- and for good reason. The software giant has increased its dividend for nine years in a row. And these increases haven't been small. Its three and five year dividend growth rates are 19.2% and 17.4%, respectively.

While Apple is a fairly new dividend stock, paying out cash to investors for only two years straight, the company's massive cash hoard, lucrative cash flow, and its commitment to future increases make the tech giant a good bet for dividend investors.

Image source: Apple.

Since Apple initiated a dividend just over two years ago, the company has approved two increases: a 15% increase in 2013 and an 8% increase in 2014. Such a short history of dividend increases doesn't offer much substance for investors counting on further increases. But fortunately, Apple said last year that it "plans to increase its dividend on an annual basis," giving investors a glimpse into its plans for its dividend in the future. Further, Apple's healthy cash position provides greater confidence that future increases can be expected. Apple's fiscal 2014 cash flow was a record $50 billion, of which only about $11 billion was paid out in dividends. And Apple's $155.2 billion in cash and marketable securities provides a giant cushion.

To be fair, much of Apple's cash is held overseas, but there are workarounds. First of all, Apple's domestic cash flow is high enough to support annual dividends and increases -- but not when combined with aggressive share repurchases. So Apple could tone down its repurchase program when the current program expires at the end of this year, leaving plenty of domestic cash for dividends. Further, Apple can continue to borrow money domestically at low interest rates, a practice that has served investors well so far. Finally, Apple may be lucky enough to be allowed to bring some foreign cash home without a heavy tax if congress ever passes some sort of repatriation tax holiday.

Overseas cash or not, Apple's strong cash flow and its mountain of cash make dividend increases look highly likely for years to come.

Apple's dividend yield today is 1.8%, $1.88 per share.