John, I think there are 2 questions. One, on the revenue and one on contribution profit. Let me take one at a time. I would say revenue, generally, when you look at Q1 and Q2 trends over the past years, Q1 and Q2 are pretty much similar because Q1, we get benefit due to seasonality. But in Q2, seasonality is not there, but we pick up due to implementations. They said, Q1 and Q2 are generally similar on top line, i.e., revenue.
This year, what we experienced was our seasonality in Q1 was much better than expected. And hence, Q2 looks like it's a small few basis points drop. But had that have the strong seasonality not happen, you would have seen Q2 growing. That said, Q2 guidance is still up year-over-year at midpoint more than 20%, and we feel pretty good about how we are going on that. And still, we are not factoring a lot of implementations, which are in outer part of the year. But if things go well, the way it went in Q1, we might see an upside there. We're falling a prudent approach.
Let me go on the second part of the question on contribution profit. And this stems basically from why we call contribution profit as our secondary metric. And the reason is, John, and as we tried to explain earlier, quarter-over-quarter, contribution profit could bounce around a little bit due to multiple factors. And that's one of the things which is not totally under our control. There's increase in average payment amount, changes in payment mix, biller mix, all these primarily business mix, I would say. This could make it happen that one quarter looks strong as the other quarter does not. And while I'm on the topic, I'd also like to say in Q1, we saw approximately 30% contribution profit growth year-over-year, which is higher than the revenue growth of 25% approximately. This has happened in the past as well.
In fact, last year in Q3, it happened and Q1 and Q2 of '22, it happened. So at times, it could be higher than revenue at times it could be lower. But to end the topic, I would say for the whole year, revenue and contribution profit both are more than 20%, and they both are pretty much lowly aligned, and we are trying to still take a conservative posture in the calculation of contribution profit.