I have a long list of reasons to buy Roku (ROKU 2.75%) stock.

The media-streaming innovator's international market expansion is in a very early stage. The company is growing sales, users, and cash profits at a remarkable pace. Rumor has it that Roku could be a buyout target in 2025. And the stock is staying down despite these pending catalysts, making it an incredible value.

Roku's secret sauce

I could talk your ear off about any of these potentially stock-boosting catalysts and then some. But I haven't even mentioned the biggest reason to buy Roku stock yet.

You see, the low stock price largely rests on soft ad sales on Roku's media-streaming software platform. The weakness is part of a sector-wide downturn in the digital advertising sector, and this distressed industry is on the verge of a huge upswing.

You don't want to be left empty-handed when this sea change plays out. It may not happen in 2025, but time is running out.

Three steps from plunge to rebound

The path from Roku's ad-based downturn to a roaring comeback is very simple:

• The inflation crisis put a damper on targeted ad sales in 2022. Why spend big money on effective advertising when no one is ready to buy what you're promoting?
• Roku's stock plunged despite strong user growth and a dominant market position. The adtech market's slump gave Roku bears plenty of tools to hold the stock down -- despite consistently strong earnings reports.
• A post-inflation economy should see more consumer spending and give advertisers access to big budgets again. Roku's large user base and effective ad-spot platform will benefit greatly from this ongoing market refresh.

This is a firm prediction, not a blind guess. Many companies in the online advertising industry are already reporting great revenue growth, signaling a strong recovery. Most of them are not as undervalued as Roku, though. That's why I recommend Roku's stock over other digital ad specialists.

Roku will soar in the next two years. You can quote me on that.